so i did something pretty stupid a few days ago i washed my truck (2002 supercrew fx4 5.4l) i decided to wash down the engine compartment thinking everything should be sealed good enough for a rinse well i guess not ever since ive had a misfire i went to the local parts store and they scanned it for me and said #8 cylinder misfire so i went home pulled off the #8 coil and the plug started the truck to blow out any water and checked the coil and its working i know first hand (the second stupid thing i did) ive never changed the plugs in the truck so i went and picked up new ones and put them in and still had a service engine light so i decided to swap the #8 coil with the #5 and if the #5 is the cylinder misfiring then that should be the problem right? well its never that easy now i have a truck still misfiring and no light on to throw a code where do i go from here besides a shop to get someone else to fix it?

 

some misfire codes require that at least three misfire events occur within a certain number of cycles before the check engine light goes off. If you have access to a code reader, you may find that you have a pending code. If you have $25 to spare, replace the plug and the coil pack you swapped which is you likely culprit.