Okay, let me try to be thorough so JBrew won't yell at me....

I've searched a butt-load of threads and would anticipate a recommendation to replace all the COPs with new DG508s from UNEEK SUPPLY ($84 for a set of 8) and save the ones that are still okay for spares. But are there any other suggestions from anyone who has had the following problem?!? Thanks.

My 4x4 auto-tranny 2001 F150 Supercab has 154K mi and aftermarket dual exhausts (they bypassed one CC). It ran great until the 5.4 started running rough (stuttering) about 1500 RPMs a few months ago, so I had the #2 COP replaced, which cured it until a couple weeks ago. It started stuttering again, this time in the range from about 1000 to 2500 RPMS, but it straightens out (for the most part) when I stand on it. It won't throw a CEL or code, but the 'service engine' light does work when you turn the key without starting it.
It was due a tune-up, so I had that done and they swapped the newer COP around with a couple others on that bank to see if the problem changed. It didn't. There's no manifold or vacuum leaks and they cleaned the MAF. It idles and revs flawlessly, but under load it stutters from the start unless I mash the pedal.............
Incidentally, the CEL was on periodically after the duals were put on, and there was a code for the CC problem and one for a fuel tank issue I fixed with a new (locking) gas cap. The CC bypass CEL stopped coming on after a couple months on it's own?!?
I also had the fuel filter replaced a few months ago.
I don't do much of anything repair-wise, I was a cop most of my life and have very little mechanical experience......

 

How many miles are on the spark plugs, and what brand are they?

 

The tune-up I mentioned was done early last week. Plugs were Motorcraft. They have about 60 miles on them.

 

bypassed 1 cc? assuming thats suppose to mean catalytic convertor, then thats one problem. how'd they bypass it? or do you mean they cut it out? there are 2 cats per bank, if you cut 1 out you need to do the same with the same one on the other bank.

for the tuneup- did you use dielectric grease? you can get a full set of 8 coils off ebay for 80 bucks, just type in dg508. is there any water down in the spark plug bores? check the heater core hoses, make sure they arent leaking where they are clamped.

 

Yeah, they cut out one cat converter bank for the dual exhaust conversion.

We checked for coolant leaks and all the plug bores were dry.

The mechanic who does work for me said he uses dielectric grease.
He has a 10th generation F150 and so does the shop owner. That's one reason I take mine there. They work on a lot of Ford trucks.

The mechanic recommended letting him change all the coils but said to buy them off the Net, cause they are cheaper. Until it throws a CEL code he said the fix is just a crap shoot. He drove it a few days last week to see if it would show a CEL but it never did.......

 

Search Ebay for DG508. About $80 a set from Global or Uneek.

 

Yeah.... $84 for a set of 8 DG508s @ UNEEK Supply. I just wondered if there was anything else I could check before spending that much on labor (after getting the parts).......
Thanks fellas!

 

you can do the coils yourself. all you need is dielectric grease and put a thin film of it on inside wall of the boots at the plug end and then use a 7mm socket and ratchet to pull the little screws out holding each coil down. then put the new ones on. it only takes a few minutes to do all the cops.

 

Found a better deal on eBay after all. They list the COPs under all different vehicles, but it looks like these have the correct numbers to fit many apps including my 01 F150 5.4L !?! They say "new w/o box", but claim to pack them in styrofoam peanuts....... That won't hurt anything will it?
http://cgi.ebay.com/ebaymotors/ws/eB...=STRK:MEWAX:IT

I didn't know how easy it is to replace the COPs. Should have researched it now I'm retired and have time to learn a little about shade tree mechanic work....

Thanks again guys and for especially for the replacement instructions, Matt.

 

I would spend a bit more and get them from a known reliable vendor such as Global or Uneek.

http://cgi.ebay.com/ebaymotors/NEW-I...=p4506.c0.m245

 

Sorry......

 

sorry again...

 

Well, I took your advice and ordered the coils from UNEEK off eBay Motors. Now all I have to do is practice taking them off and putting them back on........
Thanks again.