Hi I have a 2007 GXP 5.3L and have fixed alot of stuff on this car and down to one last problem.
Current problem: HIGH IDLE
History to fx: The car was throwing a P0121 code which has something to do with the throttle body, so I followed the proper procedure for an electronic throttle body, turned the key right 2 clicks with car not running, had a friend step on the gas which opened up the throttle body, used quality throttle body cleaner and cleaned al ot of carbon buildup from around the throttle body, friend took foot off gas, put all back together, started car and code was gone, no engine light anymore!
However now when I first start the car it idles fine at about 600 RPM's, however when I put it in gear and push gas it then idles at 1100 to 1500 RPMs. Sometimes when sitting at a red light for a while it will go back to 600 RPM where it is supposed to be.
I have tried resetting the cars computer to recalibrate the electronic control by disconnecting both battery cables for over an hour while pressing the break, honking the horn, trying to start the car to de-energize any capacitance... this did not do any good as the HIGH IDLE still persists.
Help!
