hi all,

im asking this question on behalf of a friend in the UK, he has a 91 camaro TPI (presume V8??) anyway it just failed the emissions over here because the CO2 was 7% and the limit is 3.5%. Last year the car past and has only done 200 miles since. It has had oil change etc.

i presume the car is running rich, so the problems are O2s, AFM, temp sensors??

is there any other reason why this could be have any of you had any problems??

thanks

 

are you sure the reading was for co2 and no co? co2 is the effciency of combustion, the higher the better. co would be fuel ratio, and if high, it could be running rich. if thats the case, change the air filter, check the air pump operation (if eqipped), clean the mass air flow sensor, check or replace the o2 sensor, and drive the car more so it will clear out the cobwebs. if any of that doesnt work, try an intake cleaning such as seafoam. i personally dont think it does anything, but other people swear by it.

 

yeah i asked him that and yup its CO2, UK emission say we can have 3.5% but his was 7%. Anyway he had bought a 14" air cleaner base or something which he too back off and put the stock one on and all is fine. Ill have to do some reading up about this CO2 stuff. It seems all backwards that we are not allowed high figures of CO2 but it means the car is running more efficiently.

 

Then he must have TBI (a carburetor-esque FI unit), not TPI. Possibly he didn't transfer the temp sensor probe from the base of the old air cleaner to the new one? That would sure do it.
Here's a pic of when I put an aftermarket air cleaner on mine. You can see the probe to the left of the injector pods.

 

yea, please verify whether its tbi or tpi.