The computer is running the engine rich because of the lean mixture reading from the sensor. check wiring to the sensor. Check for vacuum leaks on the engine that would allow more air into the system

Answered by Jacobandnickolas (expert)
57,318 answers provided

Thx for the repy
I have been chasing this for 2 months now and have become quite frustrated (almost traded it in last week for a C6)!
--- I checked the wiring from the o2 sensor to the ECU - good continuity - performed shake and pull test on connectors - continuity still ok!
Can I use starting fluid (ether) for the vacuum test -- spraying around the vac hoses and manifold? Dont want to break what isnt broke!
Could this be an injector issue- partial clog or misfire causing lean condition? Wouldnt think so or it would show itself regardless of engine temp but I am an old points and condenser mechanic and dont know what I am talking about!!!!!!!!

Response from lilredyugo
1 question asked

It could be an injector issue. As far as the starting fluid, you may want to consider starting fluid. It works too but isn't quite as flamable. Whatever you do, have a fire extinguishier near by. If either hit a hot enough surface, it can ignite.

Answered by Jacobandnickolas (expert)
57,318 answers provided