Mark-87-951

Catalytic converter replaced 6/2008
O2 sensor replaced 2006

I passed 4/2010 with these results
HC 1.12 (1.40) pass
CO 13.00 (20.00) pass
NOx 1.97 (3.00) pass

But failed to day with this:

HC 1.87 (1.40) fail
CO 12.00 (20.00) pass
NOx 2.96 (3.00) pass

I'm thinking my O2 sensor is the culprit.

dillon410021

It depends on your afr. Also, I have blown a cat out pretty fast when I was running rich. what mods if any are done to the car?

carlege

mark you are aware that you have 2 months left before you're emission exempt.

Ben951S

... I'd wait the 2 months. Though a wideband would be good to know your AFR if modded, or if you don't want to replace your o2 sensor.

dirtyTurbo

I've had nothing but good luck with those "guaranteed to pass" fuel additives. Totally different car, but still 200k miles

Dave W.

I agree, many WOT blasts on a high boost turbo car will wear down the cat faster. I usually get 2 years out of mine.

Mark-87-951

I have a huntley chip and boost was turned up to 15 however it will not get above 11 for some time now. I think the wastegate is weak and I have a TIAL still laying around that I need to install.

My plates expired in Oct so not sure I can get away with waiting 2 months to be exempt. I already bought a 30 day extension as well.

I think my turbo blows oil so that would reduce the life of everything downstream. I could take it to the station that got me passed when it was the catalytic converter, which they replaced. It would just bug me if it was the O2 sensor which I can do myself.

I might be able to justify upgrading to a WB if I have to change the O2. heh

Mark-87-951

Ok, my brain is a little slow lately, would the boost not reaching 15 while using those chips screw up the emissions by running rich? The narrow band gauge doesnt appear all that rich, but it is narrow band, so questionable on that score.

dillon410021

boost doesn't matter much as they tend to not boost when on the dyno. I kept trying to get a log from my smt6 for the dyno test to see just how they were driving it but each time it set it to record, the guy ended up stalling the car and when you turn the key off to restart it, the laptop loses communication.

Mark-87-951

They didnt stall my car but when he first got it moving he was a bit surprised by the clutch, which is not stock. It's only one step up from stock but the car did lurch forward. heh

Mark-87-951

I looked around a bit online. Indiana tests vehicles back to 1976.

carlege

damn. i guess you better get it fixed then. Try the 02 sensor since its easy to change. Ive got a spare O2 and Cat stored away just in case. Look around you can get great deals. Got the cat used for 60 and went to an auto store and got an o2.


Giving us a summary of your vehicle and mods wouldnt be a bad idea either so people know what your working with

quinnfiske

How many miles on your O2 sensor? These things are supposed to be replaced as a normal maintainance item every 30k to 60k miles depending on who you talk to. I replaced mine and it had a significant impact on my numbers.

951kaos

+1 on replacing the O2 sensor; as mine failed emissions last spring and replacing the original sensor with 52k miles on it cured the problem. Also make sure the catalytic converter is good and hot; a good cruise on the highway enroute to testing helps and try not to shut the engine off before testing if possible also helps; if the engine cools while waiting, the engine management may restart slightly rich on a cool day.

Mark-87-951

Replaced the O2 sensor and failed even more, all readings went up.

HC 2.29 (1.40) fail
CO 16.20 (20.00) pass
NOx 3.78 (3.00) pass

I guess I'm just going to have to take it to a certified techinician next week while I'm on vacation. Indiana is lucky I dont buy a 1975 something or other and give their emissions crap the finger