I have an 03 Chevy Tahoe, 5.3L V8. I am getting the error P1516 Reduced Engine Power. I have taken it to several shops. Most recently they replaced a modulator that is located in front of the driver, bolted up against the frame closest to the driver. I never suspected this part, but he wanted to try it. I advised them to check the G103 Ground Wire as stated in the TSB for this issue. They said they bypassed that ground by grounding somewhere else, and that wasn't the issue. On diagnostic check he said the TPS and TAC were showing no discrepancies when he was able to duplicate the Reduced Engine Power. Now he wants to replace both sensors and the throttle body. I think this is a waste of time, but I don't have another solution. The problem only presents in the morning. After stopping and restarting 5 or 6 times it will let you drive it the rest of the day. I believe this is because the computer is set to test the data sets when the car goes from 40 degrees F to some magic number. I really am not mechanically skilled at all, but I know a little. Any advice is appreciated.
Monday, September 24th, 2012 AT 12:44 PM