Originally Posted by ProfessorDave

OK, so a fwe weeks after clearing the P0300 (random/multiple cylinder misfire) the MIL came on again this morning. The conditions were almost identical to the first time (temps in the 40's, damp after overnight rain).

This time I did not clear the code. I have an oil change appt. at a dealership I've heard is Z and mod friendly (I haven't owned the car long enough to have been to any dealership) in 2 weeks, and want to see if the MIL goes off on its own. The idle speed is up (1000 - 1100 rpms), which, from what I've read, is often related to a vacuum leak when this code is thrown.

Here is my dilemma: Do I leave the light on and have the dealership service dept. address it (with the slight chance they may blame tampering with the EVAP canister - the cover was removed and a line heat wrapped as part of the FI exhaust install), or just clear it again (the idle returned to normal when I cleared the code last time).

I'm open to any thought you guys might have