Hello Everyone, I am new here.
I want to try and help someone with my past experience with my Check Engine light. I have a 2004 Pontiac Grand Prix, GT2 and I kept getting a reduced engine power, which is incredibly annoying and dangerous. I had the above codes, which kept pointing to the accelerator pedal sensor assembly. i went to NAPA auto parts and brought a new accelerator pedal assembly and installed it. The check engine light went out, but came back on the next day with the same codes. What I found out was, that this assembly is VIN specific to each car. The assembly has to be a factory AC Delco and be the one for your car. I got the assembly from the Chevrolet dealer and installed it. (take 5 minutes - two bolts) The check engine light went off on its own, and has never come back on. I wish I would have known this before I got it diagnosed for $100 and bought the assembly from NAPA auto parts for $104, which I could not return and then had to buy the AC Delco unit for $135.
I also replaced the throttle body assembly, before I replaced the accelerator pedal sensor assembly for $250. Try the AC Delco accelerator pedal assembly first and see what happens.
I hope this helps someone.