The Check engine light keeps coming on and every time it is the p0300 code. Not sure what exactly is causing the problem. It only comes on when I'm driving over 15 miles and when driving and just applying very little pressure on the pedal is when i can feel it start to stumble or hesitate. Never a problem when accelerating. I have an OBDII with live data to help me troubleshoot the problem, but don't really know what they the components should be reading as far as the MAF and MAP sensors. Compression test check out ok and as far as ignition i really don't think that could be it either because only time it has a problem is when adding just the slightest bit of pressure to the gas pedal. Anyone have any ideas to what i should look at or do?