1988 Gmc Service Engine Light

[cprdnick]

Mine was doing exactly what you described. When you run your codes it will come up with a 34 or something close to that, it's a malfunctioning EGR like stated above. AutoZone could not find that code for a Chevy P/U, so we browsed the computers for similar engines and computers in other vehicles. We came up with some year model of Buick, it was an EGR for that model. So, they suggested that I remove the EGR valve and clean out the ports. I did, and my light went off for good. Now its back on and the code book says its either the ECU or the knock sensor, lol. I'm having problems all around with my truck.

BTW, MD, your problem sounds different from what I'm talking about. You need to have your codes checked as well. Don't quote me, I'm gonna make an uneducated guess and say it could be your TPS.