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help needed misfires.

S

SapphirePit

New member
So ive been searching and no luck.

Problem- multiple misfires, po301, abs/tc codes, and o2 codes.

Background- 2000 GTP, 168k, stock except 4" cone on TB.
Light has been on (SES) for 2 months now due to me removing the rear o2 sensor. The other day I floored it to pass someone on the freeway and the SES started going crazy and she started misfiring. At first it was only when I engaged boost or under heavy load (uphill). the nexxt day it progressed to anything more than 10% throttle. I changed to XP104s and new wires. No luck. Noticed one of my ICMs was loose so I went to the JY and pulled an extra. Swapped them around and still the same, only now its random misfires and no particular cylinder. Went to Advanced and scanned the car, only random/multiple missfire shows. However I did notice it was at 22* timing....... bad or good???

Next I went to the cat. Cut it off completely. Seamed to do a little better but now you can definitely hear the misses/backfires. LOL.... tried spraying starter fluid around the vacuum lines but no apparent leaks. I do have an oil leak from the rear valve cover but I doubt that is related

Resolution- only things I have left are
-front o2
-chipped piston
-faulty PCM
_egr

Any other thoughts??? Im leaving in a week to start doing long haul trucking, and id rather not have to come home to deal with this.
 


You mean you had a coil pack that was loose?

The ignition control module "ICM" is what the coils bolt too, that can be bad and cause the random misfires.

22º timing at idle is normal.
 
If a coil was loose on the ICM maybe the ICM is shot now. Have you triple checked the plug wire order? It's easy to swap a few and still have it run somewhat fine, just with a miss.

I would think if you had a chipped piston then the misfire would be contained to just that cylinder, but could be wrong.
 
Thats what I figured. The ICM is definitely a possibility. Coil packs have been swapped around. So I guess its back to the JY tomorrow. any thought on the front o2 sensor?
 


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