I have a 2003 f150 2wd and I think it might just be bad gas but the engine is puttering and feels underpowered while going down the road. The whole truck will start to shake and like I said it just feels underpowered and sounds like its puttering. Put a full tank of gas 2 days ago it just got to a quarter tank and all this started it has 117,000 miles on it.

 

I'm also thinking it could be bad spark plug wiring. It will be a rough idle if ive been driving for a few minutes. What do you guys think?

 

sounds like a miss fire. check plugs and cops