P0300 is a Random Misfire/ P0301-P0304 specific cylinder misfire
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 usually indicates a vacuum leak or bad gas.
A misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.
Saturday, March 29th, 2008 AT 3:56 AM