Look for some help or good info. I have a 03 Yukon XL 5.3L with 56K miles on it and I'm trying to fix a rough Idle. It only Idles rough a stop, my RPM sits at 500 and I could feel the vibration in the steering wheel and pedals from the idle. Please any advise would be great. Again the trucks runs great and the idle is steady but just rough at around 500 RPM

Your idle sounds to low. Could be an EGR valve not closing off all the way. Try cleaning. You can test by turning the EGR valve upside down and fill one side with water. If it leaks to the other side it will also leak exhaust.

It could be that the throttle valve is hanging up in the throttle body because of carbon deposits. GM has a service bulletin out for this condition: #04-06-04-040. It involves cleaning the carbon off of the throttle valve, and cleaning carbon from the throttle bore in the throttle body.

These systems are electronic throttle control (drive-by-wire) and the electric motor sometimes has trouble controlling the idle speed when carbon buildup in the throttle body causes it to hang up. The bulletin also includes a check for PCM software to make sure it is operating on the latest calibration to correct for this concern- after cleaning the throttle body. The dealer would have to update the software for you IF the PCM needed it.

It could be that the throttle valve is hanging up in the throttle body because of carbon deposits. GM has a service bulletin out for this condition: #04-06-04-040. It involves cleaning the carbon off of the throttle valve, and cleaning carbon from the throttle bore in the throttle body.

These systems are electronic throttle control (drive-by-wire) and the electric motor sometimes has trouble controlling the idle speed when carbon buildup in the throttle body causes it to hang up. The bulletin also includes a check for PCM software to make sure it is operating on the latest calibration to correct for this concern- after cleaning the throttle body. The dealer would have to update the software for you IF the PCM needed it.

Would that cause the vibration in the steering wheel and gas pedal? Also what should my truck be idling at? Thanks for the reply, going out out of my mind.