Hey i have a 1994 3.4 camaro. The car has 194,000 miles but the motor has been rebuilt. It runs like a dream but when ever I let it down revv in 4th or 5th gear my SES light comes on. I have brought it to aamco but their scanner could not pick up any codes. I have changed out my O2 sesor, egr valve, plugs, wires and had a new cat put on but nothing has solved this problem. When it comes on i do not notice a loss in power. Thanks

 

just throwing it out there...but i had a mustang that had an aftermarket cold air intake installed with a cone filter, and it had a small crack in the rubber connector piece that goes onto the pipe of the intake. that was causing my check engine light to come on...i guess irregular amounts of air coming in at different RPM's did it. if you have something like that set up on your car, you might want to check it out too.

 

Stop "down revving" in 4th and 5th gear.