So twice now my car's CEL flashed a bit when started up after sitting for 2 days and then after a short period just remained on. Went to autozone and found out it was "Cylinder 2 misfire". Well the car wasn't misfiring at all so I reset the ECU and it went away for a good 2-3 weeks.

Now it's back.

Now during the first 10 seconds or so while the ECU flashes and the car was just started, I DID notice a slight hesitation- like the timing was off. The door shook a bit (had it left open).

But then it corrected itself and everything is smooth.

So since it's not consistently running rough I've ruled out the Spark plugs (also because they're under a year old). I ran injector cleaner and I doubt it's the injectors- again because the car runs fine.

So is it an IAT valve? Since it only ran slightly rough in the first 10 seconds? Anything else?

THanks!

 

....

 

Got my CEL checked out at Autozone:

P0301 & P0302 - Cylinder 1 & 2 Misfire.
P1300 - "Random Misfire"
P1399 - "Random Cylinder misfire detected"

Last one defines causes as "Blocked EGR passage" & "Valve clearance out of range", others suspect Vacuum and ignition checkups...

eh?