I've had a puzzling issue for quite a while now. I believe my car is running rich, but I cannot make sence of how. My exhaust pipe is covered with carbon and my bumper is starting to turn black also. I've tried to make sence of why there's so much carbon, but can't seem to come up with something that makes sence. I think it's running rich, but the cal should take care of that. I currently work at GM Powertrain, so I've been asking around, but no one seems to know why the ECM isn't compensating for the increased airflow. I have a CAI, high flow cat and muffler (2.5 in pipe). Anyone have suggestions for a solution? Or ways to truly figure out what is wrong, and to fix it?
Driving an Ecotec, testing future Ecotecs