2001 Jeep Grand Cherokee Q&A
2001 Jeep Grand Cherokee Question: I have Engine code P0304 which I was told " Misfire on that cyl..
I also have while trying to drive my JGC a flashing Engine light (which I was told is a cat getting ready to fail or has failed... Total loss of power while driving, I can only drive like an old man out for a sunday drive. I replaced the ignition coil pack and it didn't help. - gobluemikespike
Have you checked the spark plugs? is 304 the only code came up? - TristanReal
Flashing light means you have a misfire that may damage the cat. conv. if not repaired, not a failed/failing cat! These are possible causes for code PO 304: ignition misfire on # 4, injector blockage or defective injector, no injector pulse to # 4 injector, low compression or gross vacuum leak at # 4 cyl. Check to see if anything has chafed wire insulation to injector 4. ie throttle linkage/bracket etc. This imisfire or dead cylinder is the reason you have no power! Also the reason for the flashing light. - pushrod
By now the amount of money you have spent would have been spent by taking it to a professional to have it diagnosed it properly. The loss of power by now is because you drove it to long with the check engine light flashing. You probably do have a bad cat by now. You do need to do a basic compression check on all 6 cylinders. If it's not mechanical than it's electronic. - PARTS GUY