2008 Cobalt SS automatic had intermittent rough idle, reduced power and when accelerating would sometimes lag and eventually kick in. Worse on incline. No codes, no CEL. ---------------- Resolution - changed plugs (very old) and cleaned throttle body. All fixed, runs great. When cleaning the...

Been chasing a rough idle problem on my wife 2005 LT 2.2 Changed the plugs, swapped a new(used) coil pack, new ICM, cleaning the throttle body. Hunted for vacuum leak (didn't find one) Lastly the battery is going dead, Took to the car to Advance their battery testing machine, said the...

A while back i bought a GMPP SRI and when i put it on and started the engine there was a very rough idle. I immediately shut the engine of made sure everything was connected and started it back up and it idled rough again. I gave it a few revs and the check engine light came on. I let it run for...