Hey guys,
So last week I started my car in the morning, everything started and sounded normal until I looked at my dash. There was an immediate solid check engine light. The car was idling at about 1100 rpm. Anyways I drove it to work and it seemed completely fine (power and smoothness in the curve were all there just a high idle). I reset the car the light went off and everything went back to normal.
Fast forward a week to today (320 miles driven), I started the car and again got a check engine light upon cold startup with the same high idle when warm. I scanned and got the dreaded P0300 for a random misfire.
Now I have checked for vacuum leaks in the intake track (tightened down all clamps as I installed some post mafs 8 months ago) and check for exhaust leaks (there were some after the cats but I don't think that would code for a p0300). I reset the code and have driven it 50 miles and everything seems normal.
I am wondering if it has to do with the fact I had only a 1/4 tank of gas at the time and didn't give the pump a chance to prime the system to fuel pressure.
