Emissions -- Bah Humbug!

[SoCalZR1]

Hello everyone. Before I get into the smog headache I just wanted to introduce myself. My name is Mike and I live in The OC. I am new to the forum but not to the Registry. Just looked, I have a registry sticker on my car from 1996. The sticker is okay but the car is not looking as good as back then. :-)

Anyway, the problem. The poor beast had been sitting around too much and I decided to get it back up to snuff. I replaced the bad fuel pumps and all 16 injectors. They were leaking bad and I almost had a hydraulic lock once. All seemed good after that. Went to get a smog check and then it was not as good. It almost passed but missed HC at 15 MPH.


HC
Max allowed: 77 (Max was 110 last time it was checked. Go figure!)
Measured: 115

Nox
Max: 541 (772 allowed last time)
Measured: 437


Went home empty handed.

Drained fuel, since it was old and filled with new; Cleaned and re-oiled K&N; removed DRM PROM and inserted stock; replaced spark plugs.

Since the car is 1990 it has to go to a "Test Only" station. Took it to a regular smog first and just had them do a pre-test. Numbers were great! HC was in the high 40s, NOX below 200. That was just eyeballing it.

Confidently returned to "Test Only" and the non english speaking, ignore that I am here dude and he ran it again.. FAIL:

Now HC was good but NOX failed:

HC
Max allowed: 77 (Max was 110 last time it was checked. Go figure!)
Measured: 70

Nox
Max: 541 (772 allowed last time)
Measured: 738

What gives?

I will say that the pretest was done in first gear at 15mph. The robot dude at "Test Only" says it should be second gear. Really!? Second gear for 15MPH? That means 1271 rpm.

Any ideas. Would new O2 sensors help (easy)? Why the sudden NOX problem? I know I changed a lot of variables after the first, but I can se the problem there.

Any ideas would be much appreciated.

[Coupe89]

Just an FYI. A pretest still gets sent to the state. Its the state way out. If you failed the test.

I'm working on mine to get pass smog also.
I noticed the test from the pervious owner that failed was at 1500 RPM's mine it a 5 ticks ocer on CO...

[SoCalZR1]

Originally Posted by Coupe89

Just an FYI. A pretest still gets sent to the state. Its the state way out. If you failed the test.

I'm working on mine to get pass smog also.
I noticed the test from the pervious owner that failed was at 1500 RPM's mine it a 5 ticks ocer on CO...

They did not enter VIN info so probably no big deal. The good thing was they would heat up the cats and the run the test. Not sure if that made a difference. Interesting that I passed great at 1500, just not at 1271 at a different location.

Good luck on yours.

[C1ANDZR1]

Damn, I'm glad we don't have to deal with that crap in south Georgia.

[SoCalZR1]

Originally Posted by C1ANDZR1

Damn, I'm glad we don't have to deal with that crap in south Georgia.

Be real happy you don't!!!

[Coupe89]

One thing I noticed with mine. I dont have the stock chip.
That might be why I'm on the edge of passing.

Is you chip stock?

[SharkPilot]

I wonder if the calibration of the individual machine has anything to do with the varying readings?

In April my '91 passed fine and the limits had not changed since 2008.
The limits for HC were: 112 @ 15mph and 86 @ 25mph
For NOX it was: 778 @ 15mph and 717 @ 25mph
And for CO: 0.72 @ 15mph and 0.60 @ 25mph

I think I would try going to another location and make certain that they have the correct vehicle information entered. Years ago my truck failed miserably because they had the GVW set too low. Once that was fixed it sailed through just fine.

Like you I am in SoCal so we should have the same standards. It is supposed to be against Federal law to change the standards but I don't trust this state with anything. That being said, the numbers on my print-outs are indeed consistant.

I hope this helps,
Jim

[tomtom72]

Mike. Welcome back!

Do you have a scanner? I ask because it might be a good idea to do a closed loop scan @ idle to see if the O2's are getting lazy....along with seeing the fuel numbers and a few other data items.

Did you add a big bottle of techron to the fuel? That helps me pass the NYS smog inspection.

Off the top of my head, how are the coils and wires, PCV's? I hate to start guessing.

One thing is the CATs must be hot, if they do these tests with cold cats we don't fare so well.


Tom

[SoCalZR1]

Originally Posted by SharkPilot

I wonder if the calibration of the individual machine has anything to do with the varying readings?

In April my '91 passed fine and the limits had not changed since 2008.
The limits for HC were: 112 @ 15mph and 86 @ 25mph
For NOX it was: 778 @ 15mph and 717 @ 25mph
And for CO: 0.72 @ 15mph and 0.60 @ 25mph

I think I would try going to another location and make certain that they have the correct vehicle information entered. Years ago my truck failed miserably because they had the GVW set too low. Once that was fixed it sailed through just fine.

Like you I am in SoCal so we should have the same standards. It is supposed to be against Federal law to change the standards but I don't trust this state with anything. That being said, the numbers on my print-outs are indeed consistant.

I hope this helps,
Jim

Thanks for the input Jim. I am in Tustin so the 10 mile radius should mean the same limits. :-)

I was told that the standards changed a few months ago. It is a little hard to believe that we need to meet higher standard than last year, but this is California I guess. I also have tried to find that actual standards online without luck so far. I am going to try a different station and see what happens.

I think the one thing that is strange to me is that my NOX supposedly went up.

Thanks again.

Mike

[SoCalZR1]

Originally Posted by tomtom72

Mike. Welcome back!

Do you have a scanner? I ask because it might be a good idea to do a closed loop scan @ idle to see if the O2's are getting lazy....along with seeing the fuel numbers and a few other data items.

Did you add a big bottle of techron to the fuel? That helps me pass the NYS smog inspection.

Off the top of my head, how are the coils and wires, PCV's? I hate to start guessing.

One thing is the CATs must be hot, if they do these tests with cold cats we don't fare so well.


Tom

Hi Tom,

I have a scanner (3120) but have frankly only used it in static mode. I am not sure if it does real time. I'l go check. Any recommendations on scanners if not.

I did not add any techron or other additive. It may be worth a try. I might swap out the O2 sensors just because they are inexpensive and 20 years old.

I have spark gap a bit high at 042. I might drop that to stock, but I doubt that matters.

In any case, thanks for the input, much appreciated!

Mike