Just Failed CA Smog. Now what?

[Okiedoke]

Originally Posted by 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.

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]

Originally Posted by 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.

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.

[Coupe89]

The O2 sensors.

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

[5ABI VT]

Originally Posted by Okiedoke

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]

Originally Posted by Coupe89

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 and here 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.

Passenger Side (From the bottom) best pic I have....

[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]

Originally Posted by 5ABI VT

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.