My rig usually idles at 500 rpms, she has 81k on the clock.
Yesterday she started up and was idling at 1000 rpms and the engine was shaking. I was getting a P0300 Random Misfire and P2308 Ignition Coil C Secondary Circuit.
I changed out the plugs last summer about 8k miles ago with the NGK plugs. Had no issues since the install. So I decided to change out the plugs for the Autolite APP985. Started her back up, engine was still shaking, code P0300 was gone but still had P2308 showing up.
I did change out the Ignition Coil Sept last year. It was the Crown model #56041476AA, paid $113 via Amazon. I was pressed for time so I bought the BWD model #18240464 at Advance Auto Parts and paid $104.
So with the plugs and coil rail replaced she started right up, no codes/shake and shes back to idling at 500rpms.
Hopefully this will help other late model TJ owners.