okay, so a little background,
truck has been in my family since we bought it, its now has 121,572 miles on it. it was a good running truck with nothing wrong with it until i drove it from texas to north carolina. on the way up here, i got the cel, and my heater core went out. this was back in september, when i got up her, i did a basic tune up on her,
new plugs
new fuel filter
new air filter
oil change
i replaced the DPFE sensor
and PCV valve.
i had one coild go bad, go a used one put on it (number 3, went because it was supersoaked in coolant) a week later it another went out. so i replaced them all the week after christmas, well this weekend i developed another miss fire, i got my codes read at the school, and i have a cylinder 7 miss fire, i want pull the cop and check resistance on it to see if that is the cause of the miss. (don't have a scanner with me to do the move and see if the miss moves)

also what else should i check to eliminate a electrical problem causing the miss, and what should i check to eliminate other problems to hopefully figure out whats wrong with my truck.

 

And what is the truck? What cops did you buy? What brand are the plugs, PCV valve, and DPFE sensor?

 

the truck is an 01 f-150 5.4l screw
and all the parts i have bought for the truck have been OEM parts.

 

OEM as in Motorcraft-branded? Those cops must have cost you a small fortune. Did you use dielectric grease in the boots?