P0300 Random Misfire could be caused by vacuum leak and fuel contamination-
Engine running rough/misfiring 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.
SPONSORED LINKS
Tuesday, February 16th, 2010 AT 2:00 PM