Just Failed CA Smog. Now what?

[Okiedoke]

I bought my Z just over a year ago. Presumably it would have had to pass smog at that time. This time, everything passed except for NOX. Max for the 15MPH test is 545 PPM. My Z measured 587 PPM. The 25MPH test passed with 459 PPM. The Max is 502 PPM. The car is stock except for a KnN filter. I just went through some of the CA smog related threads and there seem to be folks who got a measurement in the 200s. In this thread by Z51JEFF (http://www.zr1.net/forum/showthread.php?t=16429&highlight=smog), it looks like he passed by replacing his O2 sensors. Is this what I should try? If so, does anyone know what model and where I can get them and how many? Is there any way to tell after replacing the sensors whether it will work short of taking another smog test? Thanks!

[KILLSHOTS]

Did you have the power key in the FULL position during the test? If so, you may want to switch to NORMAL and run the test again. Ask me how I know.

[Okiedoke]

Did you have the power key in the FULL position during the test? If so, you may want to switch to NORMAL and run the test again. Ask me how I know.

Nope. I had the key in my pocket.

[KILLSHOTS]

Nope. I had the key in my pocket.
Nuts! Too bad it couldn't be something so simple. Good luck.

[We Gone]

Do you have the stock prom? Jerry's sells the O2's. Will the testers in Calf. let you run the test in a test mode to see if it will pass after you change the O2's?

[mike100]

additional ignition timing would elevate NOx, but usually the port throttle closed timing map at the lower rev ranges doesn't deviate from stock much on some tunes.

If the other numbers were looking good except for NOx you surely need new O2 sensors. Cleaned my car right up. I will need to see your exact results for a more specific diagnosis though. Another easy fix is if you have a bad vacuum leak under the plenum somewhere (you can tell by a high idle).

I got the oxygen sensors from O'Reillys- they have the proper length 3 conductor wire harnesses.

[5ABI VT]

Was the car hot when tested? have you given it a good run @ wot beforehand and clean oil? My SS failed ever so slightly.. I gave it balls to the wall for 15 mins and came back and it passed with flying colors.

[Coupe89]

First time I tried to pass smog. Failed 3 times. Changed Eprom/Chip. Passed.

Last year I failed too many times. lol

Changed out the O2's. Picked up a pair of Bosch at the local parts store. Failed
Had to change out a bad injector it had 8.8 ohm's. Failed.
Then shop noticed the key in full power. They switched the key and passed. For got about the key after I changed out the injectors.

15-518 25-452

My shop suggested to change out the cats.

[Okiedoke]

Do you have the stock prom? Jerry's sells the O2's. Will the testers in Calf. let you run the test in a test mode to see if it will pass after you change the O2's?

AFAIK, it's the stock prom. I haven't touched it at least. I doubt the tester will do a test pass. I do get a second official attempt for free within 30 days though.

[Okiedoke]

If the other numbers were looking good except for NOx you surely need new O2 sensors. Cleaned my car right up. I will need to see your exact results for a more specific diagnosis though.

Yes. All of the other numbers looked good. Here's the report:

http://i34.photobucket.com/albums/d119/harryhhsu/smog_zpschga0cwq.jpg



Another easy fix is if you have a bad vacuum leak under the plenum somewhere (you can tell by a high idle).

Now that you mention it, I haven't heard that clicking sound indicative of a vacuum leak when I start the engine in a long time. How high is considered a high idle?


I got the oxygen sensors from O'Reillys- they have the proper length 3 conductor wire harnesses.

I looked up both O'Reilly and Jerry's and found the following sensors:

1) O'Reilly: Bosch - Oxygen Sensor (http://www.oreillyauto.com/site/c/detail/BOS0/13077/02205.oap?year=1991&make=Chevrolet&model=Corvette&vi=1041297&ck=Search_o2+sensor_02205_1041297_3469&keyword=o2+sensor&pt=02205&ppt=C2181) - Part#13077 ($45.99)
2) O'Reilly: Bosch - Universal Oxygen Sensor (http://www.oreillyauto.com/site/c/detail/BOS0/15726/02205.oap?year=1991&make=Chevrolet&model=Corvette&vi=1041297&ck=Search_o2+sensor_02205_1041297_3469&keyword=o2+sensor&pt=02205&ppt=C2181) - Part#15726 ($57.99)
3) Jerry's: Delphi - Oxygen Sensor (http://www.jerrysgaskets.com/sensor-oxygen-new-90-95-7b4/) - OEM? GM PN 10137641 ($47.75)
4) Jerry's: Denso - Oxygen Sensor (http://www.jerrysgaskets.com/sensor-oxygen-denso-90-95-5c3/) - GM PN 10137641 ($59.75)

Would all these work? Which is the preferred part?

Is this something I can easily swap out or should I take it to my mechanic?

[Okiedoke]

Was the car hot when tested? have you given it a good run @ wot beforehand and clean oil? My SS failed ever so slightly.. I gave it balls to the wall for 15 mins and came back and it passed with flying colors.

It was about a 10 minute drive from work to the smog check station. Half local half freeway. I had the power key out. It's been around 2500 miles since my last oil change.

[Okiedoke]

First time I tried to pass smog. Failed 3 times. Changed Eprom/Chip. Passed.

Last year I failed too many times. lol

Changed out the O2's. Picked up a pair of Bosch at the local parts store. Failed
Had to change out a bad injector it had 8.8 ohm's. Failed.
Then shop noticed the key in full power. They switched the key and passed. For got about the key after I changed out the injectors.

15-518 25-452

My shop suggested to change out the cats.

Is there a limit to how many times CA allows you to fail or can you try as many times as you need? My registration renewal deadline is 3/8/2015. Does that mean I need to pass before this date?

[Coupe89]

Pay the registration before 3-8-15.
Dont want to get dinged on the late reg. Cal DMV wants there money....
My reg was up in Feb 2014 passed in Jul 2014

[Coupe89]

No limit.... I think mine failed 4 or 5 times before it passed.

https://scontent-a.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/1014377_460693367365347_1861979285_n.jpg?oh=8d21cb e6ec1035ac70e9b044b2fcdb03&oe=554923EE

https://scontent-b.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/10348197_529879130446770_4710429355338684666_n.jpg ?oh=a2315685442ce51ba717f0360ad39b40&oe=55542239

[Coupe89]

The O2 sensors.

the drive side is easy.
This is what I used to get the passenger side one off.
https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/1959870_463234360444581_698069164_n.jpg?oh=f6c1a2a 7776169cc91bb61cf455938e1&oe=556045DD&__gda__=1430891614_26a55dcd838d0cb71986ae497676f3a 9

[5ABI VT]

It was about a 10 minute drive from work to the smog check station. Half local half freeway. I had the power key out. It's been around 2500 miles since my last oil change.

The hotter the combustion temps are the better it will be on emissions. flip that power key and nail it a few times to heat it up and clean it out. Drive it around for 15-20 minutes with a few wot and take it hot to the test. I know you probably don't want to chance it on that but if they'll retest for free im fairly certain it would be enough to pass was for me. Oh and also the catalytic converters work better when hotter too so that may be all it needs.

[Okiedoke]

The O2 sensors.

the drive side is easy.
This is what I used to get the passenger side one off.


I found a couple of threads here (http://www.zr1.net/forum/showthread.php?p=217653) and here (http://www.zr1.net/forum/showthread.php?p=101052) about replacing the passenger side sensor.

Ummm...here comes a dumb question...where are the sensors located? Would I be able to find a diagram in the FSM?

[Coupe89]

Before the cats on my 90

Drivers side.
https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/1013757_463234447111239_864989561_n.jpg?oh=85249a5 11496bd23deb1783df7bef50e&oe=554FB354&__gda__=1432154839_7eba9bd0a7001c327853a3629892c29 6
Passenger Side (From the bottom) best pic I have....
https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-xaf1/v/t1.0-9/1908253_463234460444571_645051696_n.jpg?oh=6bf4088 ba56af19b8ce61eb92c537161&oe=55639B19&__gda__=1431481544_d164d35dc526d02e838753fd83bc399 d

[mike100]

I have the $45 Bosch ones from the parts store. They have been thru two smog test cycles now and pass. The originals were German made (also Bosch), but these are of US manufacture. One of the ones i got from Jerry a couple of years back had awfully short leads...I don't know if he is selling a different one now.

the o2's might clean up the low speed hydrocarbons a little too. They don't last forever. For NOx they have to be dead accurate as the sensitivity to lean or rich conditions elevate that gas quite rapidly. I'm sure you'll do better after you swap them for new.

[mike100]

The hotter the combustion temps are the better it will be on emissions. ... Oh and also the catalytic converters work better when hotter too so that may be all it needs.

The cats need to be hot and the coolant up to temp (so it doesn't run rich), but hotter combustion, extra ign timing, lugging in gears at low rpm etc will spike the oxides of nitrogens thru the roof. If anything, run with a chip made to be all stock except for the part where it turns the cooling fans on at 205 degrees (instead of the factory 228 deg F). high combustion temps bad, high catalyst temps good.

Basically pinging is the ultimate NOx production condition. egr normally blows a puff of dirty air right when you crack the throttle to keep combustion temp below the threshold for nox. but of course the early cars have 11:1 compression and no egr.

[Franke]

I agree with Z51Jeff and Mike100. I had the NOX issue too. Everthing passed except for that on the IM240 test. I found out that I had a lazy O2 sensor on the left side by using my Mastertech 3100 to watch the voltage swing. Replaced the O2's and passed. The new results were about 40% lower. I used the Bosch ones.

[tf95ZR1]

I just saw this thread. I feel for you, OkDok!
I had the same problem passing CA smog with my Z.
All the recs already given are GREAT ideas.
I did them all (and some others!) to jump through
the hoops to finally get it to legitimately pass the sniffer.
Let me know if you want to talk privately....

PS: Some of the steps you do, like new O2 sensors, oil change
you can think of as general maintenance for an (old) car anyway.
What's a better word than "old"?

[mgbrv8]

Move to Texas :-)

[tf95ZR1]

What's really frustrating is that the pass levels are much tougher now
than when the car was originally designed and built. So how are we
supposed to clean them up? In their minds, this is how they get rid of
the "smog machines".

I agree that the air is MUCH better now than in the 70's, so there has
to be a comprimise. As others have said, if a stock Z is running (really)
well, it should pass, maybe with a few changes/tricks.
With mods is a different story.

[HAWAIIZR-1]

I have not had my "Welcome to California" smog testing yet. I guess I am too scared to find out. Actually have not had any time to attempt registering the car in this great State. I'm considering buying a nice, stock, low mileage ZR-1 and getting rid of mine...we'll see. Thanks for sharing all the tips and tricks and I will see if I can pass one day.

Best wishes to the OP.

[Z51JEFF]

After you fail a few times you will be instructed to take the car to a referee station. This is a State owned facility,this place will make a decision as to weather the car will not pass,pass the car with an exemption or not sure after that,I couldn't get a straight answer out the guy when I there a few years ago. I got a little help from our friend in Ill when it comes to passing the test. Is it legal,I could care less. Ca has dropped the max limits on the Nox levels from 702 in 2008 down to 502 in 2014. Replacing the O2 sensors in not an easy job,at least getting one of the plugs in. I had o jump through hoops to get a bone stock 91 to pass with 20,000 original miles. What really suck,my car at 6000 original miles wouldn't pass today. I can help with the smog issue if needed.

[HAWAIIZR-1]

After you fail a few times you will be instructed to take the car to a referee station. This is a State owned facility,this place will make a decision as to weather the car will not pass,pass the car with an exemption or not sure after that,I couldn't get a straight answer out the guy when I there a few years ago. I got a little help from our friend in Ill when it comes to passing the test. Is it legal,I could care less. Ca has dropped the max limits on the Nox levels from 702 in 2008 down to 502 in 2014. Replacing the O2 sensors in not an easy job,at least getting one of the plugs in. I had o jump through hoops to get a bone stock 91 to pass with 20,000 original miles. What really suck,my car at 6000 original miles wouldn't pass today. I can help with the smog issue if needed.

Geeez, maybe I should look at the 68 Convertible instead if I plan to live in Cali for a long time? I'm starting to think my car with the Stage I cams will never pass. Thanks for sharing. Now I see why the locals say the "SMOG Nazis"!

[-=Jeff=-]

Geeez, maybe I should look at the 68 Convertible instead if I plan to live in Cali for a long time? I'm starting to think my car with the Stage I cams will never pass. Thanks for sharing. Now I see why the locals say the "SMOG Nazis"!

Locals.. heck I call the Cali Smog people that here in Chicago... Meanign they are well known as Smog Nazis outside of the Peoples Republic of Kalifornia

[mike100]

What happens in CA won't necessarily stay in CA. The above examples of lowered NOx levels on our emissions tests come from what I believe were EPA limits that kicked in during 2012 or so from some law passed back in the 90's setting tiers to be met at certain future dates. We just happen to follow that trend (or actually set them in many cases that the EPA adopts later). What worries me is if they can/will lower them any lower knowing full well our older cars were designed to meet limits of the day, not modern ones.

As it sits now...big deal, you can definitely pass the testing- it is just that oxygen sensors don't work that well when they are 20 years old- you gotta get new ones. The problem is not clean tailpipes, but the rigid visual in this state.

[HAWAIIZR-1]

Locals.. heck I call the Cali Smog people that here in Chicago... Meanign they are well known as Smog Nazis outside of the Peoples Republic of Kalifornia

I understand what you mean. The only other SMOG state I lived in was Connecticut about 15 years ago. Back then it seemed I just tested because I had too and routine, but had an issue passing. The car would have to be a POS and was running very poorly it seemed.

[HAWAIIZR-1]

What happens in CA won't necessarily stay in CA. The above examples of lowered NOx levels on our emissions tests come from what I believe were EPA limits that kicked in during 2012 or so from some law passed back in the 90's setting tiers to be met at certain future dates. We just happen to follow that trend (or actually set them in many cases that the EPA adopts later). What worries me is if they can/will lower them any lower knowing full well our older cars were designed to meet limits of the day, not modern ones.

As it sits now...big deal, you can definitely pass the testing- it is just that oxygen sensors don't work that well when they are 20 years old- you gotta get new ones. The problem is not clean tailpipes, but the rigid visual in this state.

I can see that I will have to try to get you to help me to pass when the time comes. I have not even looked into all the stuff I have to replace to pass visual since no C.A.R.B. approved stuff. I did buy a stock air cleaner so far and exhaust manifolds/cats from a 95 take off with 2K miles.

[-=Jeff=-]

Off topic:

Hawaii, when did you relocate to Cali? I must have missed that

[HAWAIIZR-1]

Off topic:

Hawaii, when did you relocate to Cali? I must have missed that

I had to suddenly relocate to Cali last May after I returned to Hawaii from Japan in March. Long story, but basically for a job offer after my position in Hawaii being obligated to someone else returning from overseas. Thanks for your thoughts.:cheers:

[mike100]

I can see that I will have to try to get you to help me to pass when the time comes....

The one saving grace you have is that your car is not yet assigned to any particular zip code and bringing it in-state for the first time will get your target limits assigned to unenhanced area levels (higher limits). The next time will be the enhanced urban area test at the tighter limits though.

[Z51JEFF]

I can see that I will have to try to get you to help me to pass when the time comes. I have not even looked into all the stuff I have to replace to pass visual since no C.A.R.B. approved stuff. I did buy a stock air cleaner so far and exhaust manifolds/cats from a 95 take off with 2K miles.

I can help when the time comes.

[HAWAIIZR-1]

The one saving grace you have is that your car is not yet assigned to any particular zip code and bringing it in-state for the first time will get your target limits assigned to unenhanced area levels (higher limits). The next time will be the enhanced urban area test at the tighter limits though.

Thanks for the info and I have to dive into this more. I know they are going to penalize me for not changing title and all over knowing I brought it in last summer. They want their money (use tax) even if it is sitting in my garage with Hawaii storage title. I thought I might sell it so did not want to bother until I make a decision. Thanks again!:cheers:

[HAWAIIZR-1]

I can help when the time comes.

Thanks for the offer and greatly appreciated. I have a few issues to address when I have some time before I can even think about trying to SMOG it. I wish there was a way to get a test to just see where I am at without them putting the car in the system.

[Z51JEFF]

I see on reason why you can't do a pre test. Getting the car to the testing facility is the problem. Use a trailer or get a temp pass from the DMV.

[Hib Halverson]

Did you have the power key in the FULL position during the test? If so, you may want to switch to NORMAL and run the test again. Ask me how I know.

Ok. I'll bite.

How does some one from Mesa AZ know you can "pass" the CA Smog Check only with the secondaries disabled.

[Hib Halverson]

What's really frustrating is that the pass levels are much tougher now
than when the car was originally designed and built. So how are we
supposed to clean them up? In their minds, this is how they get rid of
the "smog machines".

I agree that the air is MUCH better now than in the 70's, so there has
to be a comprimise. As others have said, if a stock Z is running (really)
well, it should pass, maybe with a few changes/tricks.
With mods is a different story.

"tf95ZR1" gets a "Beacon of Reality" Award.

The reason the max. limits for the Smog Check have been getting incrementally higher is that the State of California wants to drive old cars it believes are "high-polluters" off the road and the 2G ZR-1s are considered "high-polluters". Because there are so few of them, the politicians have nothing to loose by forcing them off the road or out of the State. Sadly, this NOx problem is really tough for 90-92s which lack the EGR valve.

Here are some tips:

Fresh fuel
Clean combustion chambers and piston tops
Stock spark schedule
Proper O2 sensors. I use Densos. I think they are better than Bosch or Delphi. PN 2343005 $28.79 from Rockauto.com
Cats really f'ing hot.
ECT as low as it can get after getting the cats really not

For those with '93-'95 who flunk NOx...buy a revised cal from Marc Haibeck which turns the EGR on at 14-mph rather than 17-mph.

[HAWAIIZR-1]

I see on reason why you can't do a pre test. Getting the car to the testing facility is the problem. Use a trailer or get a temp pass from the DMV.

I will make time to check out the SMOG station that is walking distance from my house to see what is required (they tested my other 2 DDs). I believe to get the temp pass I will have to transfer ownership and all and don't think I can try a SMOG test with my Hawaii title/no reg.

I just realized that you are only 45 mins away. It seems there are at least a 1/2 dozen ZR-1s within the area now. You guys ever get together?

[Okiedoke]

ECT as low as it can get after getting the cats really not

What is ECT?


Sadly, this NOx problem is really tough for 90-92s which lack the EGR valve.
I had a thread a while back debating whether to keep the '91 or "upgrade" to a '93-'95. Looks like I should add this as a point to the upgrade side.

[Okiedoke]

It seems there are at least a 1/2 dozen ZR-1s within the area now. You guys ever get together?

I didn't realize there are so many of us in the Bay Area now. :dancing Z51JEFF looked over my Z when I bought it, but not aware of any group get togethers. I'm certainly game though!

[Z51JEFF]

I will make time to check out the SMOG station that is walking distance from my house to see what is required (they tested my other 2 DDs). I believe to get the temp pass I will have to transfer ownership and all and don't think I can try a SMOG test with my Hawaii title/no reg.

I just realized that you are only 45 mins away. It seems there are at least a 1/2 dozen ZR-1s within the area now. You guys ever get together?

If you can get the car on a trailer and get it to Fremont I can talk to somebody about doing a pretest. As far as a get together,I stopped trying to get people together,they just aren't interested.At one point I thought it would be great to get some ZR-1s together at one of the summer Good Guys shows.

[HAWAIIZR-1]

I didn't realize there are so many of us in the Bay Area now. :dancing Z51JEFF looked over my Z when I bought it, but not aware of any group get togethers. I'm certainly game though!

I had no idea either and have been so busy since moving to pay attention. It's a thought and if nothing else meet at a Cars and Coffee at the Blackhawk Automotive Museum later this year. This past summer I saw 3 Zs there and could not find the owners.:cheers:

If you can get the car on a trailer and get it to Fremont I can talk to somebody about doing a pretest. As far as a get together,I stopped trying to get people together,they just aren't interested.

Okay, I'll see what I can find out when I get ready and thanks for your thoughts and offer. My bad memory and maybe we already had this conversation. Look at WAZOO with over a dozen guys that meet regularly and pull motors or whatever together. Great bunch over there and just met up with two of them in Wash, D.C.; came out of their way by Metro to meet up.:cheers:

[Z51JEFF]

I had no idea either and have been so busy since moving to pay attention. It's a thought and if nothing else meet at a Cars and Coffee at the Blackhawk Automotive Museum later this year. This past summer I saw 3 Zs there and could not find the owners.:cheers:



Okay, I'll see what I can find out when I get ready and thanks for your thoughts and offer. My bad memory and maybe we already had this conversation. Look at WAZOO with over a dozen guys that meet regularly and pull motors or whatever together. Great bunch over there and just met up with two of them in Wash, D.C.; came out of their way by Metro to meet up.:cheers:

The white-red 91 was mine. I just talked to Cliff -Dynamite- a few days ago about getting some Zs together, he's about 150 miles from but said he would be interested in getting some people together. Ca has the most ZR-1s so we really need show the Boys from Illinois that we can play too!

[HAWAIIZR-1]

The white-red 91 was mine. I just talked to Cliff -Dynamite- a few days ago about getting some Zs together, he's about 150 miles from but said he would be interested in getting some people together. Ca has the most ZR-1s so we really need show the Boys from Illinois that we can play too!

Okay, I know Todd was there (Coupe89) too and there was a Black one with some heads in the hatch area, but parked on the far side parking lot.
I don't know if Steve Jasik frequents this site, but I know he is on the list server side and by you near San Jose. I don't know, the FBI and WAZOO have a tight group there. But no reason we can't have a NORCAL group. I am on the fence with putting down roots here and love it....so does the wife so that is half the battle.

[Z51JEFF]

Okay, I know Todd was there (Coupe89) too and there was a Black one with some heads in the hatch area, but parked on the far side parking lot.
I don't know if Steve Jasik frequents this site, but I know he is on the list server side and by you near San Jose. I don't know, the FBI and WAZOO have a tight group there. But no reason we can't have a NORCAL group. I am on the fence with putting down roots here and love it....so does the wife so that is half the battle.

To be honest with you I'd really be interested in seeing what your car would do on the smog test with the mods you have.

[Coupe89]

The owners were too busy look at other people cars :-D

[Z51JEFF]

Ive only seen 3 ZR-1s at this Cars and Coffee GTG.One was a red 90 or 91 a black 91 that the guy that owns it hasn't got a clue as to what hes up against when he needs help with the injectors,didn't really want to have a conversation and another black car that was leaving when I was.For those in the area this thing is a mind blower.Where else can you find an original Ford G.T.40 parked next to some rusty,clapped out Rat Rod?

[HAWAIIZR-1]

My apologies to the OP for bringing up all kinds of other subjects to your post.

Thanks for the tips and tricks posted that will help me when the day comes and like Z51Jeff said, I am curious to know how far off I am to meet Cali sniffer.

Let's try to make an effort to meet later this year!

Craig :saluting:

[Dynomite]

the FBI and WAZOO have a tight group there. But no reason we can't have a NORCAL group.

There are two difficulties for organizing ZR1 groups in CA......

Distance.....CA is 1,000 miles North to South and while you may have A ZR1 in CA the distance to another ZR1 also in CA is prohibitive for meeting up.

Emissions Issues make it next to impossible to Modify ZR1s in CA so those that like to "tinker" on the LT5 are rare in CA solely because of Emissions Requirements and Rules on Alterations to the Engine of any kind.

Just Saying :cheers:

In South Dakota there are also two issues.......Not Many ZR1s in South Dakota and the Winters Prohibit ZR1 Driving......And if you do not have a Heated Shed almost impossible to Modify a ZR1 during the Winter Months.

Just Saying :cheers:

Keep us posted Craig on the CA Emissions Situation :handshak:

[HAWAIIZR-1]

There are two difficulties for organizing ZR1 groups in CA......

Distance.....CA is 1,000 miles North to South and while you may have A ZR1 in CA the distance to another ZR1 also in CA is prohibitive for meeting up.

Emissions Issues make it next to impossible to Modify ZR1s in CA so those that like to "tinker" on the LT5 are rare in CA solely because of Emissions Requirements and Rules on Alterations to the Engine of any kind.

Just Saying :cheers:

In South Dakota there are also two issues.......Not Many ZR1s in South Dakota and the Winters Prohibit ZR1 Driving......And if you do not have a Heated Shed almost impossible to Modify a ZR1 during the Winter Months.

Just Saying :cheers:

Keep us posted Craig on the CA Emissions Situation :handshak:

Totally understood and why I said NORCAL (Northern California) or Bay Area if I wanted better chances. As much as I would like to meet up with the guys in Southern California (like good ol Ted Feder, etc.), the drive would kill me these days unless I were leisurely touring on vacation. When I was younger....I could do it. Like when I moved to Connecticut from Hawaii and shipped my car to LA, drove to Florida (West Palm Beach) to visit a friend and then up to Connecticut to report in for duty a little over week later.

Yes, I am ready to give up and get a stock Z to live in CA so I can drive. I could not in another SMOG ruled country like Japan for 3 years with a big paperweight in the garage. Well, you already know the saga. Thanks for your wishes and thoughts.

[rhipsher]

You can buy mine. It passes every time.
http://i301.photobucket.com/albums/nn63/keeno1970/emmisionstest2.jpg
:)

[Okiedoke]

Before the cats on my 90

Drivers side.
https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/1013757_463234447111239_864989561_n.jpg?oh=85249a5 11496bd23deb1783df7bef50e&oe=554FB354&__gda__=1432154839_7eba9bd0a7001c327853a3629892c29 6


Ok. I put front of the car up on race ramps and got under there to take a look. It looks like the sensors are pretty far back at the rear of the front tires. Not much room to work. Does the sensor use a 18mm wrench? My largest was 17mm, so I tried an adjustable wrench for now. The sensor is really tight in there! Any suggestions on how to loosen it or just get a 18mm wrench and use brute force?

[Z51JEFF]

Ok. I put front of the car up on race ramps and got under there to take a look. It looks like the sensors are pretty far back at the rear of the front tires. Not much room to work. Does the sensor use a 18mm wrench? My largest was 17mm, so I tried an adjustable wrench for now. The sensor is really tight in there! Any suggestions on how to loosen it or just get a 18mm wrench and use brute force?

The sensors use a special wrench.

[Okiedoke]

The sensors use a special wrench.

What kind and size? Like the ones Coupe89 posted in this thread?

http://www.zr1.net/forum/showpost.php?p=219544&postcount=15

[We Gone]

What kind and size? Like the ones Coupe89 posted in this thread?

http://www.zr1.net/forum/showpost.php?p=219544&postcount=15

Don't use an adjustable, 7/8 will fit or just go buy a muffler shop and have them change them.

[HAWAIIZR-1]

http://i78.photobucket.com/albums/j86/hawaiizr1/IMG_0878_zpsad2142d5.jpg

Here is a photo of an O2 sensor socket, KD 3259 that should be available at your local auto parts. :cheers:

[HAWAIIZR-1]

You can buy mine. It passes every time.


:)

There are some unbelievable deals these days on ZR-1s, but I would rather buy local that I know of passing "CA" emissions as well as save on the transportation costs. Thanks for the offer (if it was to me).

[Coupe89]

I have both sockets. But the longer one did fit for me. Too tight of a space...
I used the one I pictured.

[glkuntz]

The O2 sensors.

the drive side is easy.
This is what I used to get the passenger side one off.
https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/1959870_463234360444581_698069164_n.jpg?oh=f6c1a2a 7776169cc91bb61cf455938e1&oe=556045DD&__gda__=1430891614_26a55dcd838d0cb71986ae497676f3a 9

May I ask where you purchased the socket on the left side of your picture of tools you used?

Any help much appreciated.

Gary

[Z51JEFF]

The O2 sensors.

the drive side is easy.
This is what I used to get the passenger side one off.
https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/1959870_463234360444581_698069164_n.jpg?oh=f6c1a2a 7776169cc91bb61cf455938e1&oe=556045DD&__gda__=1430891614_26a55dcd838d0cb71986ae497676f3a 9

I have the tool on the left and this is what I used on both sides.

[glkuntz]

Totally understood and why I said NORCAL (Northern California) or Bay Area if I wanted better chances. As much as I would like to meet up with the guys in Southern California (like good ol Ted Feder, etc.), the drive would kill me these days unless I were leisurely touring on vacation. When I was younger....I could do it. Like when I moved to Connecticut from Hawaii and shipped my car to LA, drove to Florida (West Palm Beach) to visit a friend and then up to Connecticut to report in for duty a little over week later.

Yes, I am ready to give up and get a stock Z to live in CA so I can drive. I could not in another SMOG ruled country like Japan for 3 years with a big paperweight in the garage. Well, you already know the saga. Thanks for your wishes and thoughts.

Welcome to Northeren Ca.

Yes having a ZR1 here is a challenge and I agree it would be nice to get a conversation going between some of the NorCal owners. I can see from this thread that you're are in Pleasant Hill, I'm in Danville and Someone else is in Livermore. There's at least three in a small geographic area.

Might I suggest that we meet initially at the Blackhawk Cars And Coffee which is held on the first Sunday of every month. It's a neat event with up to 700 plus cars of all types that show up. http://www.blackhawkmuseum.org/carsncoffee.html

I always go and I bring various cars, but if there is interest I'll be sure to bring my Red 90 ZR1.

If you have not been to Blackhawk you should attend some of their Saturday morning lecture series. Upcoming are Howden Ganly Formula 1 Driver, Lyn St James who has driven everything and Pete Brock who will be making a presentation on the Shelby Daytona Coupe. Last year he did a presentation on the 63 Stingray that he helped design. See their website for more info.http://www.blackhawkmuseum.org/

I realize this tread is not necessarily the right place to discuss this, so if need be we can start a new thread for Norcal owners.

Any thoughts?

Gary

[glkuntz]

I have the tool on the left and this is what I used on both sides.

Thanks for your reply.

I was actually wondering where the left tool could be purchased. Any help?

Gary

[Coupe89]

I got them at Harbor Freight.
I'm always at Cars and Coffee.

Sometimes I bring my Z or Firebird.

[Z51JEFF]

Thanks for your reply.

I was actually wondering where the left tool could be purchased. Any help?

Gary

Can't remember where I got mine but if your local you can borrow mine,I'm in Fremont.

[tf95ZR1]

I can see from this thread that you're are in Pleasant Hill, I'm in Danville and Someone else is in Livermore.
There's at least three in a small geographic area.

I realize this tread is not necessarily the right place to discuss this, so if need be we can start a new thread
for Norcal owners.
Gary

Go into Forum --> Club Regional Areas --> Pacific Region
and post up any events to attend. Get the word out and
they will GROW! Let us southerners know if there is a special
meeting and some of us will come up!
Ted

[Okiedoke]

Thanks for your reply.

I was actually wondering where the left tool could be purchased. Any help?

Gary

I found the following when I was searching last week:

1) O'Reilly (http://www.oreillyauto.com/site/c/detail/PFM0/W84008/N2546.oap?ck=Search_N2546_-1_3535&pt=N2546&ppt=C0195)
2) Harbor Freight (http://www.harborfreight.com/3-8-eighth-inch-offset-oxygen-sensor-wrench-97177.html)

When I was at O'Reilly's to buy the socket, I found out you can rent a 3 piece O2 sensor socket set (different brand than the one they sell) from O'Reilly's for free for 48 hours ($26 deposit that's refunded when returned). I rented this, but there just wasn't enough clearance for me to even get the socket around the sensor. I'm not sure if this is just specific to my Z or whether the socket they rent is just too thick.

[glkuntz]

I found the following when I was searching last week:

1) O'Reilly (http://www.oreillyauto.com/site/c/detail/PFM0/W84008/N2546.oap?ck=Search_N2546_-1_3535&pt=N2546&ppt=C0195)
2) Harbor Freight (http://www.harborfreight.com/3-8-eighth-inch-offset-oxygen-sensor-wrench-97177.html)

When I was at O'Reilly's to buy the socket, I found out you can rent a 3 piece O2 sensor socket set (different brand than the one they sell) from O'Reilly's for free for 48 hours ($26 deposit that's refunded when returned). I rented this, but there just wasn't enough clearance for me to even get the socket around the sensor. I'm not sure if this is just specific to my Z or whether the socket they rent is just too thick.

Thanks for the leads. I'll check out Harbor Freight as the O'Reilly one looks identical.

Gary

[Hib Halverson]

What is ECT?(snip)


Engine Coolant Temperature.

[Z51JEFF]

I'm thinking about going on the 1st if anybody wants to meet me there.

[glkuntz]

I'm thinking about going on the 1st if anybody wants to meet me there.

By there do you mean the Blackhawk Cars and Coffee? If so I plan on being there. I usually arrive by 7 in order to get a spot in the upper lot.

Gary

[Z51JEFF]

:USFlag:By there do you mean the Blackhawk Cars and Coffee? If so I plan on being there. I usually arrive by 7 in order to get a spot in the upper lot.

Gary
That's the one Gary. You wouldn't happen to own a Black 91 would you?

[glkuntz]

:USFlag:
That's the one Gary. You wouldn't happen to own a Black 91 would you?

Nope, Red, Black interior.

See you there. What color is yours?

Gary

[Okiedoke]

The failed report:

http://i34.photobucket.com/albums/d119/harryhhsu/smog_zpschga0cwq.jpg



I changed out the O2 sensors, engine oil, and went to the smog place recommended by my mechanic with the engine hot and I passed!! I don't think the O2 sensors did anything for NOx. The 25 MPH measurement actually went up from 459 PPM to 519 PPM. The average is 223 PPM. If anyone knows why my NOx is still so high and how I could get it down, I'm really curious to know. All of the other measured numbers are all below the average.

I think what made the difference is not anything I did to the car but in the values entered for the smog test! The previous smog place put "CORVETTE" instead of "CORVETTE ZR1" as the Model. They also entered this as a "California" instead of "Federal" car in the Certification field. Entering these values correctly actually raised the NOx MAX levels from 545 PPM to 757 PPM (for 15 MPH) and from 502 PPM to 696 PPM (for 25 MPH).

The passing report is below:

http://i34.photobucket.com/albums/d119/harryhhsu/Smog_Pass_zpslvbzpyso.jpg

[Coupe89]

Hummm...... interesting......

Glad you passed :-D

[mike100]

...

I think what made the difference is not anything I did to the car but in the values entered for the smog test! The previous smog place put "CORVETTE" instead of "CORVETTE ZR1" as the Model. They also entered this as a "California" instead of "Federal" car in the Certification field. Entering these values correctly actually raised the NOx MAX levels from 545 PPM to 757 PPM (for 15 MPH) and from 502 PPM to 696 PPM (for 25 MPH).



This is huge...I will double check my previous tests to see how it was tested.

As for the high Nox. Probably a small vacuum leak or old catalysts.

[glkuntz]

[QUOTE=Okiedoke;220729]I changed out the O2 sensors, engine oil, and went to the smog place recommended by my mechanic with the engine hot and I passed!! I don't think the O2 sensors did anything for NOx. The 25 MPH measurement actually went up from 459 PPM to 519 PPM. The average is 223 PPM. If anyone knows why my NOx is still so high and how I could get it down, I'm really curious to know. All of the other measured numbers are all below the average.

I think what made the difference is not anything I did to the car but in the values entered for the smog test! The previous smog place put "CORVETTE" instead of "CORVETTE ZR1" as the Model. They also entered this as a "California" instead of "Federal" car in the Certification field. Entering these values correctly actually raised the NOx MAX levels from 545 PPM to 757 PPM (for 15 MPH) and from 502 PPM to 696 PPM (for 25 MPH).

I'm curious how the smog guy got away with using Federal instead of California certification. It's a Ca car is it not? The 49 state Federal standards are no doubt less strict than Ca. which is potentialil why the Max limits were higher, about what they used to be in Ca.

I sure hope you actually get your registration and that I can convince a local guy to do the same.

Gary

[Franke]

Would the difference be that cars SOLD in CA would be equipped somewhat differently than cars sold in the other states and therefore would have different emission requirements? For example I once saw a CA car that had 2 evap canisters in it vs the same model non CA that only had one.

[Okiedoke]

I'm curious how the smog guy got away with using Federal instead of California certification. It's a Ca car is it not? The 49 state Federal standards are no doubt less strict than Ca. which is potentialil why the Max limits were higher, about what they used to be in Ca.

I sure hope you actually get your registration and that I can convince a local guy to do the same.

Gary

There was some text written in the engine bay by the air intake. There's supposedly a difference between a car build for CA vs a car than can be legally sold in CA. I would need to do a search to see if I can find it again, but I remember reading a post in these forums that said all the ZR-1s were the same. There were no special ones made specifically for CA. Maybe others with more knowledge in this area can shed more light on this topic.

[mike100]

Maybe in the 70's the CA car was quite different, but these days the certification thing is mostly a bribe to the state to be able to sell cars here. Many manufacturers choose to have two types to save on that fee while others with less complex distribution channels often just make the cars 50 states and pay the fee for every single one. Remember some NE states adopt CA regs... but anyways... it isn't important to this discussion because the federal vs CA status on the CA smog check system doesn't matter. Mine came up as a federal car and got the low limits.

It would seem more likely that the model designation 'ZR1' is more important to the limits as it had an extra 100hp and low production count which deserves the higher limits imo.

[mike100]

I'm going to check my certs later when I return home. When I bought it from the last owner, he lived in an unenhanced zip code. This would be the other reason for higher limits... but maybe not- maybe these guys aren't selecting the proper sub-model if what you say is true. You didn't change your mailing address in the last couple of weeks did you?

[mike100]

Another point: look at the test weight- 3500 lbs vs 4000 lbs. That will elevate the NOx so they adjusted the numbers. more resistance on the rollers basically. probably included full tank of fuel and passengers (gcwr probably).

This is an awesome find for CA ZR-1 owners

[Okiedoke]

You didn't change your mailing address in the last couple of weeks did you?

LOL. No.

[Okiedoke]

Another point: look at the test weight- 3500 lbs vs 4000 lbs. That will elevate the NOx so they adjusted the numbers. more resistance on the rollers basically. probably included full tank of fuel and passengers (gcwr probably).

This is an awesome find for CA ZR-1 owners

I did happen to have a fairly full tank of gas. I also had my second top in the trunk. I had the second top for the failed smog too.

Or could the state have just happened to change the limits in between the two tests?

[mike100]

I did happen to have a fairly full tank of gas. I also had my second top in the trunk. I had the second top for the failed smog too.

Or could the state have just happened to change the limits in between the two tests?

They don't weigh your car- the weight designation comes from their vehicle database and affects how much resistance the dyno provides the rollers. Basically makes the car have to push what it weighs. The ZR-1 is heavier and it seems that they have a special set of parameters for these cars that would be in our favor if you can bring it to the attention of the smog guy before he starts the test.

[Corvettes White]

After having lived here since I could drive.

The State tests cars to the manufacturer's certificate. Not the fact that the car just happens to be in the State. Now all the parts the car came with must be there and working in addition to passing the tail pipe test. And they can be sticklers about the parts. The cut off for smog testing is ’75, pre cat cars do not get tested (except maybe upon transfer.) As for the test levels having been reduced, I have a hard time believing this, unless it is related to the fact that we use oxygenated fuel, not available when older cars were built, and there is an adjustment for that fact.

As a practical matter, no one doing tests is likely to know what a Z even looks like. So if it looks stock, it will likely pass the visual test. I run a C5R in the ’99. It passes. And I looked up ’89 Z’s for my engine swap. The motor is listed in the CARB books for ’89 so a legal swap.

What I cannot legally do is go off the Las Vegas and buy a car to register it in California unless it is certified for California. They will not give me plates. But they will give me a ticket for keeping it in California without California plates. If I bought the car for my girlfriends use then brought it into California after 6 months it is now a used car and they will let it in.

What we do not have is yearly operational tests nor traffic cameras on the freeways in the middle of nowhere. There are not a lot of toll roads. The roads in most places are well maintained. On the freeways, the highway patrol officers are usually good natured. There is a lot of traffic in the main cities, no doubt. But when there is no traffic in Orange County, I commonly drive just under 80 and that is the flow of traffic. It is a big state with a lot of cars, unless you drive like a jerk, an idiot, or are talking on your cell phone without a seat belt, you are not likely to be pulled over for much of anything.

It is also interesting to note that driving styles change from community to community. LA I would rate as third world. Most of Orange County as civilized except around Newport Beach. In Newport I do not use my blinkers because the BMW’s and MB’s speed up to cut you off. San Francisco itself is a carnival. Most of the rest of the Bay Area people drive rather slow compared to SoCal. In the farm land a lot of hard working people. Most drive carefully, no extra money to pay for a ticket. As for the way north region where the marijuana grows, never been there but can imagine like a Cheech & Chong movie. Where I have constantly looked over my shoulder the most are in the states of Arizona and Ohio.

And the smog levels are very much reduced. So a tradeoff.

George

[tf95ZR1]

Congrats, Okiedoke!
I know how great it feels to finally pass.
Plus, hopefully now your Z will run even better
with new O2 sensors, etc.
And you don't have to pucker up for another 2 years!
Ted

PS And yes, I have old smog test sheets from years ago
for the exact same car (my Z) that prove the limits for
all parameters have been LOWERED. Same car, harder
to pass. Welcome to California!

[WARP TEN]

There was some text written in the engine bay by the air intake. There's supposedly a difference between a car build for CA vs a car than can be legally sold in CA. I would need to do a search to see if I can find it again, but I remember reading a post in these forums that said all the ZR-1s were the same. There were no special ones made specifically for CA. Maybe others with more knowledge in this area can shed more light on this topic.

The window sticker on my '95 lists "California Emissions Requirements" at $100, just below the Roof Package at $950. I believe the CAR was primarily an A.I.R system (which for me in Illinois is now in a box). --Bob

[glkuntz]

I thought it might be informative to show what has changed over time in Ca for those of us who have to deal with it.

My car is a 1990 Ca delivered car that I have owned since 1995. It has always passed the smog test, albeit, marginally sometimes. It has always been entered as a California spec car and with just Corvette as the model.

Below are the results from 2008 and 2010. Sometime between these two tests the limits were reduced by about 1/3 as you can see from the max allowable columns.

2008
http://zr1.net/forum/attachment.php?attachmentid=4070&d=1424968217

2010
http://zr1.net/forum/attachment.php?attachmentid=4071&d=1424968217

Additionally for 2010 the test required that the 25 MPH test be done in second gear, causing the car to essentially lug along at very low RPM. This does not represent real world driving and, while I'm not an engineer, it would seem this could contribute to the poor readings. My car, as a 1990, has no EGR valve, so trying to obtain the required results is difficult at best.

In the near future I will go to a smog station and see if they can do the test using the "Federal" as the certification, along with "Corvette ZR1" as the model designation, and if so does it makes any difference. I really hope so as it would make life a lot easier.

Stay tuned.

Gary

[phrogs]

Move out of California.

[glkuntz]

Move out of California.

Let's see, today is sunny and 71 degrees as I take the Z on a drive to lunch, Mi is 15 and cloudy. :)

I'll deal with the bureaucracy.

Gary

[mike100]

So I looked up my 2011 smog paperwork from when title transferred and it was tested properly as a ZR-1 submodel. The limits are exactly the same as the 2015 sheet posted earlier in this thread so curious that our cars caught a break on the ever lowering NOx standards. So we only need to get it under 700 ppm NOx and it's good.

[glkuntz]

So I looked up my 2011 smog paperwork from when title transferred and it was tested properly as a ZR-1 submodel. The limits are exactly the same as the 2015 sheet posted earlier in this thread so curious that our cars caught a break on the ever lowering NOx standards. So we only need to get it under 700 ppm NOx and it's good.

Wow, that is really good news. Until this thread started I never really thought about how the model was listed. Just let the smog guys do it.

It will be interesting to see what happens when I take the car for a smog and ask them to enter it as a zr1.

Thanks for your feedback.

Gary

[mike100]

I would be curious to know what the limits before 2011 were because that is about the time the hammer dropped on the standards to squeeze out older cars. I've only had this car 4 years.

[Okiedoke]

Congrats, Okiedoke!
I know how great it feels to finally pass.
Plus, hopefully now your Z will run even better
with new O2 sensors, etc.
And you don't have to pucker up for another 2 years!
Ted

Thanks! I hope so this time! It was only 1 year since I bought the Z when they sent me the smog check notification...


PS And yes, I have old smog test sheets from years ago
for the exact same car (my Z) that prove the limits for
all parameters have been LOWERED. Same car, harder
to pass. Welcome to California!


Yeah. I believe they lower them every 2 years. Although I heard that the DMV gives out a limited number of 5 year smog check exemptions at the beginning of each year. I've yet to look into this...

[Okiedoke]

Below are the results from 2008 and 2010. Sometime between these two tests the limits were reduced by about 1/3 as you can see from the max allowable columns.

2008
http://zr1.net/forum/attachment.php?attachmentid=4070&d=1424968217

2010
http://zr1.net/forum/attachment.php?attachmentid=4071&d=1424968217



The table isn't showing up for me. I just see the two years.

[Okiedoke]

By there do you mean the Blackhawk Cars and Coffee? If so I plan on being there. I usually arrive by 7 in order to get a spot in the upper lot.

Gary

I might be able to make it too. I've never been to that plaza. Will it be obvious where the "upper lot" is?

[mike100]

Yeah. I believe they lower them every 2 years....

It has held steady for a few years. They only lowered the limits in 2011 I understand. I think they were well above the allowed limits to what cars was originally certified to, but they had a margin. That margin is gone now, that's all.

If you take the exemptions, after a couple of test cycles they expect you to crush your car. The gov't isn't your friend in these matters.

[Okiedoke]

If you take the exemptions, after a couple of test cycles they expect you to crush your car. The gov't isn't your friend in these matters.

Now that's way beyond unfriendly!

[glkuntz]

I might be able to make it too. I've never been to that plaza. Will it be obvious where the "upper lot" is?

Yes it will be obvious. I will try to be there at 7 in the upper lot. Currently there is a 20% chance of rain and I won't be there if it rains.

Can you see the two tables that posted earlier now. They showed up in the post you sent saying you could not see them.

Gary

[Okiedoke]

Can you see the two tables that posted earlier now. They showed up in the post you sent saying you could not see them.

Gary
Nope. I don't know if it's just me.

[Z51JEFF]

Wow, that is really good news. Until this thread started I never really thought about how the model was listed. Just let the smog guys do it.
Neither did I and my car failed twice. What sucks here is once it's on the cars history it's pretty much written in stone. Next year I'll remember this.