5.4L V8 - 2006 F150

Changed plugs about 2000-3000 miles ago. No problem til this weekend. I noticed the CEL on.

I had the code(s) read at Oreily's today .... P0351 (COP or wiring at #1 cop/plug)

I noticed a rough idle at one point today (which is why I stopped and had the codes read) .... this is the only thing I've noticed other than CEL.

I've read all over on here and found that a number of different things could cause this code.

I plan on pulling the COP & wiring tonight and looking for any problem(s) before I start replacing anything.

Any suggestions would be apprecitated.

 

Most likely the COP itself.

Did you change the boots when you changed the plugs? Did you use dielectric grease?

 

no new boots

no dielectric grease

 

Boots are optional unless they are dried out or you are not using OEM Motorcraft replacement plugs, but dielectric grease is required. I would pull all the cops and apply it.

 

Found my problem I think........

-Pulled the bolt on COP #1
-Grabbed the plug to disconnect.... it pulled right off

The lock clip on the plug broke when I was diconnecting during the plug change. Apparently with changing temps, road vibrations, etc it can loosen.

That's where my problem it. Don't know how easy that piece of wire/plug is to replace but I need to do something to secure it.

Anyway ....... found the problem.

 

For now, try a zip tie.