When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Trucks been running poorly for a couple of weeks.
It’s a 2004 F150 5.4, read code p0304. I replaced the coil on cylinder #4 no change today I changed the spark plug which was a little intimidating but it came out without breaking and now the truck is running good again.
Try to clean snout area of cly with carb cleaner when plug out . Carb cleaner will dissolve carbon that grabs snout of plug , just don't drop anything into cly .Replace all plugs and boots, scape and clean tabs on coils ,use contact cleaner .
Its wise to use a very small amount of anti-seize on spark plug threads, nickel based is best , don't use copper .
Boots are damaged by age/heat/antifreeze/oil . Do it right and it will last 60k miles . I like to use anti seize on coil hold down bolts also .
