Been having problems with the truck running rough at an idle for 3 weeks, as well as the service engine soon light coming on. Hooked to diagnostics, which showed cylinder #2 misfire. Changed spark plugs and wires and #2 cylinder coil pack. Truck still ran rough and service engine light still flashed on intermittently. Truck seems to run worse the longer it sits without running. (i.e. overnight or after 2 hours of not running.) No codes are showing up now on diagnostics. Not sure where to go from here with it.
Engine Idle Problem on 2002 Chevrolet Silverado 2500 HD
I would suggest you continue to diagnose for a misfire condition at idle on your 2002 Chevrolet Silverado. There are a number of items you have not addressed which can cause the engine to misfire - compression loss or fuel injector issue for example. A scan tool would be of help to try and determine if #2 cylinder is still causing your misfire. If you have reached the end of your diagnostic ability and find you need the help of a repair shop please use the following link to find one near you - http://repairpal.com/directory?address=41015&car_brand_names=Chevrolet.
Thanks to everyone who responded to the problem I was having. We have discovered the issue. The air hose running from the air filter to the engine was just loose enough to allow a small amount of air to be sucked in. Also, there was a seperate connection by the #2 cylinder that was not fully connected. We used the diagnostic machine to determine it was located to the #2 cylinder. However the connection was fully connected at times which caused the code to display at random on the diagnostics.