Ive replaced the throttle body, gas pedal and 20 way connector harness to the throttle body..Still getting Reduced engine power code

Welcome to the forum. Sounds like it may be in limp mode.
What was the code # on your 2008 GP with the 3.8 ?
Are there any other associated codes, when using a good shop scanner?

Yes..1st off thank u for replying..I appreciate your time..The codes associated are P2138(throttle body) P2120(pedal position) P1125( manufacturer control) P0449( evap vent valve/ selenoid circuit)..All comes on wen car goes into limp mode REDUCED ENGINE POWER..I jus ordered the evap parts bcuz thats the only thing i didnt replace yet..Wut i hav repalced so far with all new parts is as follows- Throttle body, gas pedal w/ position sensor and 20 way connector harness with leads..I did an idle relearn procedure after puttin in the throttle body, gas pedal and new harness..Car drove for an hour then went back into Reduced Engine Power mode makin all the other hand in hand codes come back..Do u think i hav an electrical wiring issue or can it be from replacing everything except the EVAP VENT VALVE CANISTER and EVAP SELENOID ?

Sounds like a wiring issue to me.

I appreciate all of your time..Im gonna put the evap parts on n get the wiring checked out..Dont know too many mechanics that hav snap on tool or diagnostic literate..Well I'll do some research on that too i guess..Ok thanks forum friends

Your evap is not causing the limp mode. Did you have any programming done after replacing the TB and PPS?

BTW You would do well to post this is the correct forum.

I moved this technical thread to the Pontiac Section.Thanks,

Im new to the forum and really didnt fully understand what can or cant be posted , etc..I understand thanks

You're OK...That'* how we learn. I learned after only 5 times..... but I'm old....