Ok, so bare with me. This is an odd one.

2004 5.4 4wd 150,xxx miles.

Today leaving the office, the truck felt a bit sluggish. I know- 5.4 3V life, but more sluggish than usual. It was running just fine, shifting just fine, sounding fine, just felt like I was towing a couple thousand pound trailer. It would last for about 10 seconds or so and then all of a sudden, the truck would realize “oh, this is what I’m supposed to be doing” and rocket forward commensurate with how I’d expect for how hard I was pushing the throttle.

This is happened a couple times when I first got it but it was about twice over a span of 2 months then never happened again until today. Then it happened twice in the same 20 minute trip.

No pending or permanent DTC’s and my throttle position sensor didn’t seem to reading erratically when I was monitoring it. Plugs and coil boots were changed ~10k miles ago.

Any ideas?

 

Have you visually checked the FODM on top of the spare tire? That can do all sorts of quirky things. Also when was the fuel filter changed last?

 

FPDM, sorry, fat finger typing 😝

 

No idea about the fuel filter. Probably could stand a change. Never visually inspected FPDM. Probably should do that as well.

 

Update on this- still doing it, more frequently now. I’ve got a pending DTC P0351 which I understand can be a coil, wiring, or PCM. Yay!!!!

 

Something that was never asked. What brand are the coils?

 

OEM. Never replaced. I replaced the boots and springs when I did the plugs, but never the coils.

 

Maybe its time to replace the coils. The code is referencing a bad coil circuit.

 

Yeah, I’m going to start just replacing all the coils. Ford Tech Muckaloko (or however you spell it) also said that a common point of failure on the F-150 that causes this code is the PCM.

 

That's Makuloco. From what I read elsewhere, PCM failures on these trucks are pretty rare.