I have a P0300 Multi Misfire DTC on my 2001 QX4 265K+ miles. Prior to new parts installed and after I received the same code. I just replaced the injectors, coil packs, spark plugs, PCV valve and Intake gaskets which are all supposed to be potential causes for P0300. I also installed new Valve Timing Solenoids.
I also now have a P0365 Knock sensor left bank that is new after the part replacements above.
Anyone have any suggestions on how to diagnose the P0300 problem further or a fix beyond what I e already replaced?