I was driving my '98 Jeep Grand Cherokee Laredo (6cyl 4.0l 4 wheel drive) on the freeway when it, very suddenly, started shuddering badly. The check engine light came on and then started blinking. I pulled right over and shut it off. I stared it back up and the engine is misfiring badly. I had a code reader with me and it’s showing three codes. A random misfire, a cyl #5 misfire, and a Cyl#6 misfire. It will sit and idle (very roughly obviously).
There was no drop in RPMs, oil pressure, voltage or anything when it happened.
I got it home and replaced the distributor cap/rotor, all six spark plugs, and the plug wires but there is no improvement. I cleared the Codes and re-read them and got the same errors again.
Any suggestions from those wiser than I (that’s pretty much all of you here) on what it might be or what to check next?