Try this check the DPFE/EGR
A misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.
Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.
A Random Misfire code P0300 usually indicates a vacuum leak or bad fuel
Monday, January 28th, 2008 AT 8:52 PM