I can not tell if its one or the other, any place to start looking ? My battery is pretty dead could that explain a misfire? Its an original battery in my 2001 with 100k It feels like i just hit a pot hole but there was no pot hole and it only seems to act up when im in OD, light on the throttle with a slight grade, and the truck starting to work a lil. Thanks

 

Low grade misfire. If the original spark plugs are still in there, replace them, they are due.

 

Ok well maybe not the tires but just about everything on that truck is original. Replace just the plugs or the coils too? I am changing out the lower ball joints, upper control arms, Tie rod ends, shocks, battery, brake pressure switch and just had a tranny flush and need an alignment. I have just put alot of money in the truck what are these gonna cost me? Installed or do it myself? Thanks again

 

Replace just the plugs to start with. Get Motorcraft platinums, do not use antiseize, and torque them to 28 ft/lb. They are about 5 bucks each. Use dielectric grease in the coil boots and twist them back on pushing down till they are seated.

 

Wait, wasn't part of the problem with the OEM plugs was that they DIDN'T use enough antisieze and that led to them snapping into bits occasionally? I just want to clarify.....

 

Apples and oranges. The original poster has the 2 valve heads with only 4 plug threads that blow the plugs out - YOU have the sticking issue with your 3 valve heads.