P0351 and spark plug wires

[Meadowlark Lemon]

My 1997 Mountaineer has been giving me an occasional P0351 code. In my reading it looks like it could be a bad connection on the wire harness to the coil, a bad coil, or a PCM problem.

To date I have tried unplugging and re plugging the PCM and the wiring harness to the coils.

Is there a possibility that a bad spark plug wire could cause this? Also is this a 'misfire' code of something different? My understanding is that a true misfire code is P030X, with X being the specific cylinder.

The truck does surge a little under low speed / low RPM conditions (45 mph in 4th, maybe 1400 RPM), especially noticeable when it is raining / damp, which leads me to suspect the ignition wires themselves.

It will also throw a P0153, not sure if that is related, but I am going to have a close look at the connection to the O2 sensor as well.

Thanks,

Andrew

 

[J_C]

Are the plugs or plug wires original, or several years and well past 50K mi (or less if plain copper plugs instead of platinum or better) old? If so I would go ahead and replace those as it's something it probably needs soon enough anyway.

 

[Meadowlark Lemon]

Well, It is not very sophisticated, but I figured I would swap the coils to see if the trouble code followed, and it did - I went from a P0351 (Coil A) to a P0353 (Coil C). I think this is a pretty strong indication of a bad coil, but which pack contains coil C?

Thanks,

Andrew

 

[allmyEXes]

Look on the bottom of the bad coil and see if it is cracked.
Click below to see my fun with 5.0s from 2 or 3 weeks ago. Read to the end.
1997 5.0 died while driving, won't start back up

 

[donalds]

Look on the bottom of the bad coil and see if it is cracked.
Click below to see my fun with 5.0s from 2 or 3 weeks ago. Read to the end.
1997 5.0 died while driving, won't start back up

U get that plug out ?

 

[allmyEXes]

@donalds Nope! I'll be pulling the right head off of the 5.0 after the white '97 is all back together.