Anybody have troube with a 2004 supercharged grand prix with a misfire in cylinder 3 and 4. Expecially under heavy load with pedal 3/4 to all ther way down. Check engine light is blinking. Both spak plugs showing misifre.
New plugs and wires and pcv valve.
Compression is good.
You can tell a little rough miss during idle but no codes during idle.
Anybody have this trouble before? Bad gas mileage.
I do know the cat is plugged or getting plugged. So I plan on ordering one of those. Somebody said one time the exuast on the back of the converter should be 100 degress hotter than the front? That they shouldn't be the same temp. Mine are the same temp.
