2000 Chevrolet Silverado 1500 5.3 idle issues.
Hello everyone, recently I have been experiencing a strange issue with my 2000 Chevrolet Silverado 1500 with the 5.3 V8. After driving for longer distances(over an hour) when I return the vehicle to neutral and park the rpm surges to 1000-1200 rpm where the typical is \~600 rpm when the issue is not occurring. So far I have cleaned the throttle body and cleaned the IAC valve, which seemed to have helped for a few days until the issue returned. After cleaning the TB and IAC, I also used a professional scan tool to ensure the throttle plate position was closed and that the TPS was seeing the proper voltages from closed to open. At this point I’m at a complete loss as the issue has returned today and am hoping someone here has dealt with this issue in the past and can point me in the correct direction.