what may cause intermittenant p0306 when cold on 2004 Dodge Durango

misfire appears when cold, after warmup it goes away at least it does now. injector seems to be operating fine. resistance is comparable to other injectors. being a 2004 it has no plugs, wires, and such. I am not sure how to test coil or spark or what readings to look for

Asked by for the 2004 Dodge Durango