Found two wires within the bundle that were slit and possibly grounding out. Repaired them and erased codes and drove about 15 miles. No codes came back yet and no misfire of number 4. I’m about to drive it much further to find out. I can hardly believe that was my problem but no codes or misfire yet.

 

The intermittent misfire came back just now. I noticed my shifter seems a little off and I do have the p1DCF code and soon as it misfired and got the cel light, I shifted back and forth through gears a few time then back to park and it cleared up?? Could a loose linkage cause an intermittent single cylinder misfire for cylinder 4 ??!

 

You wouldn't think so, but, stranger things have happened.....

 

If anyone reads this and has any ideas lmk. Gonna try to clean all the connectors to the pcm and whatever else I can. Still getting the intermittent number 4 cylinder misfire , po304, the p2311 insufficient ionization, and p1DCF unallowed park engagement codes..