i got a 98 f150 with the 4.6L. i have been havin misfire issues since about the time the truck hit 120,000 miles. most recently i spent today changing out cyl 4 plug due to scan showing its misfire. i also put on a new egr tube that had blown apart at the lower end. went for a drive and once i hit about 2200 to 2500 rpm it started to cut out again. after about a mile or two CEL was back on-cyl #4! just a bit frustrating. this has been a reoccuring issue every couple weeks to a month now for about 5 months (usually cyl 1,4 if it helps)! any ideas would GREATLY be appreciated.

 

#4 COP if it has COPs or possible the #4 injector. Any other codes coming up? Are you sure you got the right plug? I have the 5.4 and they are passenger side front to fire wall 1-4, driver's side front to firewall 5-8. The #4 plug is one of the harder ones to get to.

ETA: Just saw in another thread you have two coil packs in the 4.6. The 5.4 has eight COPs. The passenger side coil pack could be the problem.

 

yeah i got the right plug unfrotunately. after 12-13 times of changing it i think i finally got it narrowed down correctly to the right cylinder. its got the same order as your 5.4 . for the most part thats the only code thats been showing up besides after i mess with other plug-ins and such. ill most likely bite the bullet and check on the coil pack that runs that particular cylinder and such and go from there. if that does not work or if it seems sucessful i will be sure to leave a messege. thanks a lot

 

If you have coil packs and not cops, I'd throw a new coil pack and plug wires on that side.