So last night when I got into my car the CEL was on so I called Onstar and they said it was an emissions problem. I know the gas cap is on tight so it isn't that. The only mod I've really done is the SS Exhaust from the Cat back. I've had it on for months with no issues, but maybe the change in the weather could have sparked something? What should I do from here? I'd take it right to the dealer, but I don't want to get any crap about my exhaust, is there any way I can self diagnose this problem? Could I have the code read at Autozone? Would disconnecting the battery reset the CEL?

 

dont disconnect the battery. take it to a dealer or autozone or whoever and find out what code it is. emissions covers a lot of areas on your car. it could be the gas cap like you said, or a catalytic convertor, 02 sensor, a hole in a vacuum line and a ton of other things. find out what code it is before you do anything else

 

dont disconnect the battery. take it to a dealer or autozone or whoever and find out what code it is. emissions covers a lot of areas on your car. it could be the gas cap like you said, or a catalytic convertor, 02 sensor, a hole in a vacuum line and a ton of other things. find out what code it is before you do anything else