Just registered, been reading on it for years (as a guest), Great Site!
My '03 F150 has been a great vehicle for me, 122,000 miles and hoping many more.
First time I have had an issue with it.
Started to misfire a week ago and check popped a code that Cylinder 1 misfire. Changed the coil pack and the spark plug and everything ran great for 2 days. Third day misfire when giving it gas. Ordered a full 8 pack of coils from ebay for $115.00 and just swapped out the remaining 7 coils and plugs. Ran great for about 10 miles and started to misfire again. This time I no check engine light, watching for it I noticed that the theft light occasionally flickers on. Playing / testing at any speed if I let off the gas completely and tap the gas pedal the theft light will flicker every time and it will misfire at roughly the same time. Watching closely the theft light does flicker when the engine misfires. PAT module bad? Thought the jerking when it misfires causing theft light to flicker but ruled that out by traveling rough road and not getting a flicker. Has to be PAT module occasionally cutting me off?
Thank you in advance, I do appreciate any help / advice.