I've gotten so much great advice off this board I thought I would try and help a little.
Here is my story....
I had been experiencing an intermittent hesitation, tranny(auto) shifting problem that was really hard to pin down.
I also had an intermittant vibration problem at exactly 60mph that was also intermittant.
Well finally, I was driving home and the MIL light started flashing and the car was missing like crazy.
Got home and scanned the car to find COP on Cylinder 1 tossing a P0351 and P0301 code.
Great!
At least now I can fix it.
Swap COP 1 with COP5, clear codes and the problem is now with COP 5.
Great,
Get a new COP, put it in Cylinder 5 and test the car.
After about 5 minutes, car backfires and I am missing bad again.
Go home, plug in scanner expecting to find a new defective COP....Surprise when I find COP 1 blown again!!!!
Ok, I get another COP, but DO NOT INSTALL IT because I suspect something is blowing the COP in cyl 1.
Get out my trusty Fluke and discover Green/White wire for COP 1 has a couple of megohm (I forget exact value) to ground while other COP have open circuit.
Hmm...something not right.
Unplug ECM and same thing...
Ok, that's good, at least I probably don'w need an ECM.
Bottom line, harness shorting out to EGR downtube.
It was melted!!!!!
I repair melted wires, install new COP and I am up and running fine.
Lesson to be learned: These things just don't blow for no reason.
One maybe, but certainly not 2 and certainly not on the same cylinder.
Check your harness.....
Here is my story....
I had been experiencing an intermittent hesitation, tranny(auto) shifting problem that was really hard to pin down.
I also had an intermittant vibration problem at exactly 60mph that was also intermittant.
Well finally, I was driving home and the MIL light started flashing and the car was missing like crazy.
Got home and scanned the car to find COP on Cylinder 1 tossing a P0351 and P0301 code.
Great!
At least now I can fix it.
Swap COP 1 with COP5, clear codes and the problem is now with COP 5.
Great,
Get a new COP, put it in Cylinder 5 and test the car.
After about 5 minutes, car backfires and I am missing bad again.
Go home, plug in scanner expecting to find a new defective COP....Surprise when I find COP 1 blown again!!!!
Ok, I get another COP, but DO NOT INSTALL IT because I suspect something is blowing the COP in cyl 1.
Get out my trusty Fluke and discover Green/White wire for COP 1 has a couple of megohm (I forget exact value) to ground while other COP have open circuit.
Hmm...something not right.
Unplug ECM and same thing...
Ok, that's good, at least I probably don'w need an ECM.
Bottom line, harness shorting out to EGR downtube.
It was melted!!!!!
I repair melted wires, install new COP and I am up and running fine.
Lesson to be learned: These things just don't blow for no reason.
One maybe, but certainly not 2 and certainly not on the same cylinder.
Check your harness.....