1) were there any codes present when you first used scanner (assuming no)?

2) did you drive the truck after disconnecting COP (and/or low psi)? Or at least let it idle with one COP disconnected?

The misfire code takes takes a while to trigger CEL/code

tpms may take a while too (note, after replacing my wheels (w/out tpms) it took quite a bit of driving before errors shown)

 

I went back and tried the COP again, and it worked. The CEL came on. So I ended up clearing the code after plugging the COP back in. So I guess this eliminates the ECM being bad?

 

i think it does. Seems to at least debunk the theory that your mechanic used for his diagnosis (note: in fairness to mechanic I was reading between some of the lines in your post (vs hearing from him firsthand), but based on what you wrote I think you’ve now debunked his theory/diagnosis).

 

I would try to get it out now and drive it as much as you can. See if you ever get codes and then deal with them as they come.

I’d not focus on the readiness test status, at until you log a bunch of miles.

If you don’t know age of fuel filter or condition of the FPdM - I’d do that as soon as you have the time.


edit: I’d probably also find a different mechanic.

 

I have probably logged ~300 miles since I started this thread. Since the tuneup, I might have ~50 miles on it.

The remaining issue is the assumed misfire with lack of CEL coming on.

Replacing the FPDM was going to be my next move. I have not changed it since I have owned the truck, which was bought at 70K miles and now has 190K

 

i bought my 08 3 years ago with 205k. The prior owner had just had the fpdm relaced (think it was one of his last $ spent on it before selling). You may be on borrowed time with yours (don’t know your climate). Probably good idea to at least have one under the seat until/if needed. I’ve read a lot of posts and seems some guys get symptoms/warnings and others will be running fine and left stranded all of a sudden.

 

Im going to order one tonight. Would a faulty FPDM throw a code?

 

I’m no expert on that, but I don’t think they always throw a code, especially when/if you are just starting to experience symptoms. There is a sticky thread in this (04-08) section dedicated to fpdm. Also look on YouTube for fordtechmakeuloco’s video on fpdm.

Post back as you figure out (or resolve) issues.

 

Will do

Thank you for your help!

 

So today I changed out the FPDM with a Dorman one, since I saw that was the one most were using in the sticky. It was a night and day difference in the performance from acceleration to how it ran at 50mph. Noticed it immediately, and could not get it to slip or miss. Hopefully this was the issue!