Gentlemen, I need some HELP please!! Just bought a 2003 Grand Prix GT V6 3800 and she's misfiring on Cyl#3 code P0303. Or is it ???? Already replaced ignition module/coil pack, plugs, wires, injector and now valve spring and she's still knocking away. Also having electrical issues with instrument cluster, fuel level fluctuating and temp rising. Fans do not seem to come on. Could these problems be conjoined somehow???? Man o' man I be confused.
It's a pretty significant knock at idle but goes away when driving.