I got 2 codes from my CEL, was Misfire for 1st and 4th, but i just got the coils and spark plugs replaced maybe 2000 miles ago? The spark plugs had the right gapping when they were put in, but i've also had the problem of having misgapped ones before from Volvo. It hasn't misfired since this one time.

Other info. I have a Cone filter, and i think that causes me to idle around 580RPM when everything is turned off. Also just put in a sub and amp the other week. And in summers the temp is 100+, and went down to 19. Wondering if that could have anything about it?

Thanks,
Showtek