hi i have a 91 firebird that i got like 1 month ago and got it running right but it is running very rich and i can smell the exhaust while driving it, and when i come to stop at a light it is racing at 1200rpm but idles down to 600 or so but it really jumpy like it really wants to go forward. if i am at the light for a while it throws an ses light but as soon as i drive away it goes away. if anyone has any idea what this could be please let me know.


Thanks
~Chris

 

See if you can pull the codes

 

check for vacuum leaks or ecm could be going out. Pull Metric KPA from scan tool to help tell you what actual vacuum is. If its out of range then you either could have a leak or your ecm is failing.

 

Alright so i did the paper clip thing to read the codes and i got code 12 and code 35 i already replaced the iac valve but could it have gone bad already? (Been about 1 month)

 

just curious but how dirty and gummed up was your IAC? If it was a bad as mine was, you should take the throttle body off and clean it out as well. The port for the IAC can become very gummed up and plug.