2006 GMC Sierra "run bad" Questions

...run rough at idle, runs fine driving, smells rich in exsaust Check for vacuum leaks n (broken or leaking hoses; gaskets), bad EGR valve (plugged or stuck open) or raw gas running into the intake ...

...sensor just be faulty? Changed out with others, but not new try this, disconnect map sensor while running. if it runs a lot worse or rough. map is ok. but if it does not make a difference the way ...

...head lights affects it by making the motor stop sometimes and run bad all the time. the battery is new. the alternater puts out 14+ volts. You have a bad ground cable or strap. Check all body

Engine running rough Not enough info here! Could be anything from bad injector issues to bad gas,, vacuum issues,. air flow issues,, bad plug wire,,,???

...run for a few seconds. You might need to have someone listen by the gas tank since the pump is located in the tank. If you don't hear the pump then there could be a bad ground or else either the fuel ...

...run bad? I have a 2009 GMC Sierra 5.3. Stabilitrack stays on more than not. Truck runs bad. Local mechanic put it on computer and then changed tcp sensor. Then the plugs and check coil packs. Still ...

Systems: runs good when cold, gets up to normal operate temp., comes under load giving gas, acts like running out of gas, running 3k rpm, only does between 30-40 mph. repairs already made to no ...

my 1990 GMC Sierra runs hot when ac is on only runs hot when running AC Check the radiator fan to make sure it is turning at full speed.  Could be a bad fan-clutch. 

2000 gmc Sierra 2500 I have no running lights or 2000 gmc Sierra 2500 I have no running lights or reverse lights on the rear but have running lights up front and all signals work as do the brake ...

ses light flashing, truck running rough Good Evening. I'm sorry to hear your truck is running bad, however I can give you a few points to check on. Your flashing SES light is because you have a ...