Thread: 2008 Pontiac Grand Prix

Hey guys, new here. I have a 2008 3.6L NA Grand Prix. My wife is complaining that her car is occasionally stalling when stopped at idle, and runs rough at idle occasionally, occasionally sluggish on shifting around 40-50MPH. Can't get it to duplicate for me or the mechanic. No CEL, or stored codes.

Car has approximately 102,000 miles. Did 90K service with AC Delco plugs, cleaned throttle body, MAF, gap set to factory specs, etc.

could be a bad crankshaft sensor, that would explain the stalling but not the running rough at idle. You might want to ohm your injectors to see if they're still within spec