Could be plugs, wires, cap and rotor. Replace all those and see if it helps. Probably wouldn't hurt to replace them anways. Goodluck!
I ran my IAC disconnected for almost a year, I highly doubt the IAC allowing too little air into the throttle body via the plunger assembly it actuates would cause a misfire.I had the same problem and the solution was in the IAC (idle air controller) runs between 50 and 60 bucks. what it does is make a controled vacume leak and allows for the fast idle, which is why you don't have a prob when yuo keep the idle around 1000. IF you have a low idle around 400-600 and it seems to miss, also do you have your engine light on, if so your codes will say both the IAC and a missfire, at least mine did... hope this helps.
that's usually the case since the IAC's function is to maintain idle RPM during cold starts or when the A/C compressor cycles.the IAC is usually effected more in colder climates or on cold mornings, once mine warmed up it ran better, not great but better...
it wasn't neccessary, i just wanted it to idle lower. It idled at 750 after I installed the 52mm, that caused it to creep against the brake when in gear.why was it necessary to essentially by pass the IAC in the with the bigger TB