Hello all...
Problem 2003 Grand Prix GT 3.8..
Within the past week of driving, I've noticed a stall when the engine returns to idle. If I increase throttle to around 1500 to 200 RPM then quickly return to idle the engine will stall down to about 100 to 200 RPM then back up to normal idle. It dose this constantly, but more frequent after a long drive.
Now, there are codes "DTC P0300 Engine Misfire Detected - ECU $10" and "P0302 Cylinder 2 Misfire Detected - ECU $10", this is according to what I found in Palmer ScanXL Pro.
Maybe a bad gas cap? Would this cause a misfire on one Cylinder? I've been trying to come up with a solution based on these two issues are related (Stall and now new codes)..
I can clearly hear the misfire at the rear of the car but can't determine which side the misfire is on (seems to be coming from both pipes).
I've recently replace plugs (Iridium's) and wires (GM OEM).
Thoughts?
