Hello again,
Getting code 304 for #4 missfire, which it is. Can the coil pack be bad where only one plug is effected? You would think if the coil pack for a given cylinder bank were bad all plugs on that side would be effected? Also is there a DIY way to determine if a coil pack is bad?
Thank you in advance

 

Yes to your first question. - 304 is a dead hole. Coil pack, plug wire or plug.

No, this is your layout -

 

Just pull the plug wire, throw a plug into it and fire it up. Ground that plug and it should spark. If not, check the wire, then the coil.

 

Thanks very much for your reply. All wires were pulled and tested with a spare plug grounded and all fired nicely. Stumbled on to another post where you recolected that the wiring harness, if too close to the AC accumulator would also cause a miss-fire in #4. Reading this, a light bulb went off in my head, remembering that I had removed the the electrical block to gain access to the accumulator but never charged the system and left the bolts loose and one missing for a future time. Thinking now with all bolts in and torqued the miss-fire will be eliminated?
Thanks again!