Welcome back:
Honestly, the P0602 indicates a programming error in the PCM. The remaining codes point to the reduced power and throttle issues. All of the following errors are most likely the result of the PCM.
P1125 indicates fail safe mode ( no power issues)
P1295 indicates power saver mode ( no power issues)
P1515 throttle position correlation error. (No power issues)
At this point, and I hate to say it, I feel the PCM may either need reprogrammed or replaced.
Joe
Saturday, December 1st, 2018 AT 6:27 PM