I have a 89 Grand prix with a 2.8 that idles bad after warm up.
SES on, stored code is a 45 (too rich). I have replaced the TPS and the O2 sensor. I have unplugged the vapor canister but I can't seam to find the canister control purge valve and cleaned the IAC and the housing for the IAC, none of these things has helped. The engine idles normally on start up but you can smell that it is running rich and after warm up (when the computer is adjusting for the rich mixture) that is when the idle starts to fluctuate from 1000 down to 500 RPMs.
I am banging my
Please help!!!