P1516 Chevrolet - 2003

Question

does it cost a lot of money to fix this

Answer 1

P1516 Throttle actuator performance position

This code can also set reduce engine power in the message display center, What happens is the PCM detects a out of range condition between the predicted and actual throttle position, GM has put out a TSB for a new software to be reflashed to resolve this issue,  You may just need a reflash of the PCM