I've got a 2004 with a 5.4L Triton 3V and CEL P0351. I changed the cop on #1 cylinder with the cop on the #2 cylinder and drove around for a few days trying to see if the trouble followed. I had the occasional rough idle but never threw a code or a cel until today. I drew the same po351 code and no cel. How would I go about checking the pri/sec voltage on the #1 cylinder?
Thanks

 

What you do next is test the fuel system. Then swap injectors if all is okay. Next would be the plug, - I wouldn't touch the plug until last.

If you need a plug change, -it might be time.

Being #1 , - It's the furthest away from the fuel pump. Could be the filter, maybe the pump or both.

 

thanks for responding, I just had the plugs changed a few days ago and the cel came on just a few hours later. Me being just a little paranoid, it seems like every time someone else has worked on this truck another problem pops up. I'm not pointing any fingers, I would just like to solve this problem myself if possible. The filter is no more than a few months old which doesn't rule it out. But you think this could be a fuel supply problem?

 

What plugs did you use? Its not at all uncommon for a plug to fail brand new in these motors. Especially non motorcraft.

 

I don't know but I can find out from the mechanic that installed them. I do know that he uses napa parts mostly.

 

By the way I'm new at this forum stuff. Do your replies automatically show up or do I need to refresh my screen periodically?

 

refresh

 

Fill out you info in the user control panel so your info shows up like mine does.

 

Napa doesn't carry motorcraft so My bet is its the plug.

 

lol, I went to usercp and i don't have a clue what or how to set up

 

I'll call the shop tomorrow and find out what he used but the problem seems mostly to be at idle although I did some problems under load under 45mph today. I thought a plug failure would be more consistent than that but I am rusty on shade tree mechanicing these days

 

click user cp click edit your details. fill in the truck yeart what truck and engine. Then it will show on every post. at some point someone will bring it up again if you dont..

 

Well you did the plugs just now so it seems likely one failed.

 

Gotcha on the details thing I think. So if I have a plug failure and my thinking is correct I could just change the #1 cyl and see if that clears my problem and if it does then I would go ahead and change them all. I don't think that should be a problem with only approx 30 miles on plugs should it? Or do I need to go ahead and buy that extraction tool?

 

why didn't my details show up on that last posting?