So for months we had issues with our 2004 Tahoe. Would constantly throw service stabilitrak/reduced engine power along with various codes. The 2 constant one were for the has pedal and the throttle body sensor. Replaced both of those, but kept coming back. A new one popped up for the rear wheel speed sensor. Replaced it and so far no more issues. Although it did not fix another issue we have. From a dead stop like a stop light, when you accelerate, there's a grinding/spinning noise, and the car will not accelerate unless you left off the gas and back on it. If you press the traction control button and turn off traction control it never does it. Anyone have any ideas? Sometimes it'll pop up "traction control disabled" when it hesitates. It sounds like it's coming from the front left. I'm glad we got the reduced engine power squared away and hopefully it helps someone else from throwing parts, I doubt the throttle body and petal were even bad, as they looked new when I replaced them.

 

Full scan all 4 code families is needed. P code scan is not enough. Part store free scan is not good enough either. U, C and B codes need to be checked.