07 Cobalt SS/SC
I have been getting engine power reduced at random times. It goes away when I clear the p2101 throttle actuator control motor control circuit range/ performance and p1516 codes. In an attempt to solve the problem, I installed a ZZP LS4 throttle body with the necessary adapter plate and intake boot. Now, the car idles at 1800-2100 RPM and if I hit the throttle, it goes into engine power reduced and sounds like misfires but does not throw any codes other than p2101 and p1516. Is my next step to look into a PCM? What else could be happening? Thanks in advance

 

If you weren't tuned for the LS4 throttle body... you can't properly use it. It requires some scaling changes and updates in the tune.