Find this "Dildo" under your hood. Its between the airbox and the throttle body with two rubber bends at either end. Take off the two hose clamps that hold it on and pull it off. Inside is the "Nerf Football". As you can see, it is a huge blockage to incoming air. Push on the nose cone of the Football with your thumb and it should pop out backwards. Reinstall your "Dildo" and take a test drive.
It made a noticeable difference to me.
The next thing to do is the throttle cable fix. You pretty much stack zip-ties on the excess throttle cable under the dash that otherwise keeps your truck from hitting full throttle.
The airfilter/box on these trucks is the same as the 4.0 v6. Its already oversized for the little motor. So a cheap stock replacement filter will be plenty enough.
A good free-flowing muffler would make a noticeable difference as well. Stock these trucks have some kind of goofy-ass stamped steel unit on them that I've yet to dissect to see whats inside. OEM mufflers are built to be two things. Quiet and Cheap. Flow and Tone go out the window in this equation. You can have a quiet free flowing muffler, but that would cost too much. You can have a cheap free flowing muffler, but that would be too loud for a dealer to try and sell. I personally like Thrush Turbo Mufflers, and thats what I'll be putting on my truck soon.
"What where dealing with here is a complete lack of respect for the law"
Bu"ford" T Justice
Haha, one day I hope to actually find a T/A that someone will actually part with. Condition does not matter at this point. One lady wouldn't sell me one with moss replacing the carpeting on the floorpan, and non-exsistent toe-boards.