I have an “89” Trans Am 5.7 TPI with MAF Sensor. I keep getting a code 33 so I changed the MAF sensor and it didn’t fix the problem. I checked the wiring harness for ground faults or broken wires from the sensor plug all the way back to the ECM that’s all good. So I replaced the MAF Power relay and the MAF Cleaning Cycle relay. Still the problem persist. The car runs fine but it idles up and down between 600 and 1000 when I am stopped. I also hooked my laptop up to the car and used Craig Motes software and the MAF is sending a good signal and increases smoothly with the RPM. The CHECK ENGINE LIGHT comes on every time I drive the car. Can anyone tell me if there is a way to check the ECM. PLEASE HELP!!!

 

wow no one replied to your topic in like 10 days. Check stuff like your TPS sensor or maybe your HEI, anything that can send throttle position or RPM signals to your computer, if they are bad/wrong it will think it needs more/less air from the MAF sensor and think it has a wrong reading tripping code 33

 

Thanks for the info. I have not had a chance to look into it yet but what you say makes sence. I appreciate it.

Looks like you have a really nice ride!!!

 

I had a similar problem with a tbi truck and it was the tps.

 

check the air hoses to the TB from the maf for small creaks or leaks. also check your pcv valve. a stuck open pcv valve will **** the ecm off by cuasing a vacum leak.are the blm and int high like over 130 ??