Go to AutoZone have them rear your codes for FREE. This way you will know which Coil Pack is goig bad / or is bad. If you have a 4.6L you will have only 2 Big Coil Packs. If you have the 5.4L you will have 8 Coil Packs , One coil pack for each cylinder.
Most automobiles will not start with a nonfunctioning coil pack. The coil pack will cause the spark plugs not to fire.
symptoms are: you can hear the engine missing, spitting and sputtering, loss of power...you can tell if it is a coil pack by unscrewing the spark plug that it connects to coil pack. when you look at your spark plug it should be a light grayish, white..this means the coil pack is working....it is best if you do this with new spark plugs, because your spark plugs could be bad. but you do this process until you find a bad plug then, that coil pack probably is the bad coil pack.
A bad coil pack would not smell like gasoline.
bad coil pack... replace coil pack
Then there is a no spark condition and engine will not run. If it has more than one coil pack it will miss on the cylinders controlled by the defective coil pack.
It is probably the coil pack. To find out for sure remove the coil pack from number three and switch it with the coil pack from number four. Run the engine for awhile until the light comes back. If the new code shows that the problem has moved to number three, you know that coil pack is bad. Otherwise it is probably the wire or wire connector going to the coil pack or possibly a bad spark plug. Good luck
The coil pack could be weak, or break down under load or heat. The coil can be basically checked with an ohm meter for resistance, but the only way to know for sure is to replace it.
Bad coil or coil pack.
If you have a bad coil pack the bike will not run. Take a spark plug out and reattach the plug wire then hold it to a bare metal part of the motor so you can see the bottom of the plug. Try to start the bike and see if you have a spark on the plug. If you do then the coil pack is OK. If you don't it's probable bad.
auto zone will check your codes for FREE. if you have a bad coil pack they will tell you.
Your truck has two coil packs. one on each side of the truck. I changed mine twice on my 99 expedition. I dont know the exact definition of the coil pack, but i know that they are related to the sparkplug and it's wires, and when they go bad they can cause a misfire with the sparkplugs. If you need to change them send me a message i can tell you how.