Tire size on stock changed before Gryphon

[Jackpine]

Maybe the Seafoam? I cannot imagine the tune would have this effect for any reason.

You possibly have an injector problem now that has been aggravated by that stuff. I really think your only option now is to take it to the dealer. (You should have received the "injector problem" letter from Ford.)

- Jack

[88Racing]

Few suggestions....

Clean the maf

Clean the TB

Change the fuel filter

Unplug the programmer and disconnect the battery before performing the above.....after the above is completed reconnect the battery and plug the programmer back in....

Locate and inspect the fuel pump driver module.....located on the frame crossmember in front of the spare tire.....you have to drop the spare to get a good look at it and remove it from its location.....check for cracks and corrosion near plug and backside of case.....

[Jackpine]

I keep forgetting the fuel pump driver, although I suspect if it were bad, you would not have 40 psi pressure. Clogged injectors though are always a possibility.

And, I take it you were not in "Limp Home Mode"? That should have turned the "wrench" light on, but a bigger tipoff is the coolant temp gauge would have been pegged on hot (even though the coolant temp is normal. (Your other symptoms sound a bit like limp home mode.)

- Jack