: 97 Catera misfire

11-15-05, 11:46 PM
Wife was driving home tonight and the engine started running rough and check engine light came on. I read the codes when I got home: P0301 misfire on cyl 1.
Runs rough enough I plan to check compression on that cylinder tomorrow to check for valve problem. Could a bad injector cause problem? A bad coil would misfire on two cylinders right? Any suggestions?:hmm:

Terry D. Singleton
11-16-05, 02:03 AM
Perhaps somehow, due to high condensation in the engine compartment, your two main module plug-in inside the black boxs nexts to the battery have excess build-up of moisture. A very simple solution in this case is to purchase some contact cleaner from your local electronic store. Disconnect the negative portion of your battery before during any work. Open the top lid of the enclose case and slide up the P.C.M.. Inspect for any type of moisture. On it, you will find a ground strip and two black connectors. Unplug and disassemble one connector at a time by removing the back cover with a small screw driver to allow trap water to escape and wash it down with the contact cleaner. Let air dry thoroughly, ( Or use an air hose) and be sure to reassemble it to the same way as the second cable connector is to avoid confusion. Once you had completed all work, test your cable by hooking them up, (Will only connect to their own socket) and ensure that everything works. Once you had determine that the misfire had stopped while the engine is running, go ahead and turn off the vehicle, disconnect the battery and disconnect the cable. Lubricate both pin connectors with a noncorrosive\non-conductive grease to form a good seal against future moisture buildup. Reassemble and you should be O'K.

11-16-05, 08:40 PM
It's fixed!!! I was not getting juice to the spark plug on #1 cylinder. I pulled plug out and it hissed when I removed it so I knew the valves were doing their job. I called O'Reilly Auto Parts and they said they could have me a coil pack by 3:00 pm for $188 plus tax.
The coil pack is a PITA to put in. Had to pull the wiper motor assembly to get to it. I suggest to anyone doing this to buy the heater valve and replace it then. It is real easy to get to when you pull the wiper motor assembly.:D

11-18-05, 09:58 PM

it is cake to get to the coil pack without removing the windshield wiper motor. It takes me 30 minutes tops now a days after replacing the damn thing so much.

BTW be forewarnded

if #1 went out it was more than likely due to oil in the spark plug galley. This forsaken coil packs do not withstand getting sent to ground at all. (went to three going on four).

11-18-05, 10:40 PM
What year Catera do you own? There is no way to get that coil pack out without pulling the wiper assembly! I checked for oil on the plug when I removed it. The valve cover gaskets were replaced last year and I did get a mis-fire then too. The wires were soaked in oil then.