My nephew had his plugs and wires changed because he was getting a bad surge on the highway and couldn't go no more than 40-50mph. So now those are done, he is still getting a little bit jerky. It had 112000 miles on it and he doesn't do maintence like he should.

What do ya'll think it can be, fuel filter and o2 sensor maybe.


Also he gets a rattling noise when he hits the gas and the sound comes from under the truck, could the exhaust be loose.

Maintenance on an exploder is simple and cheap. Buy two large gas cans and fill them with gas.
Pour one all over the inside, and the other split half and half between the engine and the outside of the body. With the doors open, have someone you know who smokes get inside and light one up. All problems are now solved.

OK, seriously guys, the Ford bashing on this site has gotten really old. If you aren't going to help, then shut up and go away. They don't break any more than our Pontiacs do.

Well, if he doesn't know when the last time the fuel filter has been replaced, then I'd start there. It's easy and cheap.

Is this the 4.0L V6 or the 4.6 V8? And is the check engine light on?

As far as the rattling, I'd check the heat sheild on the cat. converters. They're known to rust and rattle. Most people just remove them.

Jay

my pops has a 03' mustang GT, i like it

thing could beat a stock GTP pretty easy though

Stock for stock, it would be a good race, but it wouldn't go "easily" either way, if both drivers knew what they were doing. It only has about 20 more hp and torque. That's not much.

Its the 4.0 liter V6, He changed the spark plugs and wires and that cleared most of the problem. But I know he needs the fuel filter done probably.

He also gets a rattling noise coming from under the car when he hits the gas in park, I thought it was something loose. what could this be?

I'd be willing to bet its a heat shield on the cats. With the truck cooled down, crawl under it and smack the heatshields w/ your fist and I think you'll find that they rattle.

If that's not the issue, then I would look around for something else in the exhaust. Give everything a good shake and you'll probably find the rattle.

Jay

Yep thats the word I was looking for (heat sheild) could not think of it at that time. I will do that and see what I come up with, thanks fordman.

Jerkiness and rattling could be the transmission. My dad had an 02 XLS for work and the transmission was absolute crap by the time he got rid of it at 175k. The trans usually takes a few seconds to catch after the 1-2 shift and a rattling is present during acceleration throughout 1st gear. Still ran with this problem for a few thousand miles until a completely failed wheel bearing made his company decide it was time for a new one.