i got a 97 f150 5.4 i had it scaned it came up with #7 misfire so i changed the plug and coil then reset the com it drove fine for about 10miles and started running rough when im driving i took it in and had it rescaned and it came up #7misfire what should i do

 

what brand coil and what brand plug? did you use dielectric grease? did you just glob the end of the boot with it? if so take it back off and clean it up. use a qtip and coat just the inside of the boot with the grease and then slide it back onto the coil and spring. then put it back in and see what you got.

 

i used a durlast coil and autolite plug i did what u sead to do and it still is running rough what do should i try next

 

Replace the Autolite plug with a Motorcraft, and get a stock Motorcraft coil, or get a whole set off Ebay for what you would pay for one.