So the new engine in my car is idling rough and I'm getting random misfires in cyl 3 4 5 6.. It's runs fine when cold its just when it warms up... It has new wires new plug new coil packs and the vacuum lines are fine. Any ides?
The mods are headers 1.9 rockers 3.3 pulle zzp ECM.. No cat zzp exhaust