I am trying to fix my friends mothers 08 GP with the series 3 3.8L. Getting a P0300 General misfire code. Checked plugs and wires, even to the point of disconnecting plug wires one at a time and the engine runs the same. Definitely missing at idle, smooths out at higher revs, definitely down on power and mileage, I believe it is running in "safe mode". Replaced all 6 injectors, since that seems to be a pretty common problem, I also read a TSB for that model year about a problem with the injectors getting plugged up. Car does run a bit smoother but still missing. Any help would be greatly appreciated. Thanks in advance!!
