Hey guys first post here (read a lot but never made an account cause I never had to post.) i have a 2004 fx4 with the 5.4 liter. The truck has almost 290,000 miles on it now on the origional motor but it's starting to have more and more problems and sinse the truck is clean (people guess 70,000 miles) and has a new trans I figured it was worth it to buy a new motor. I have countless codes on the truck (most of which related to the old motor) and some are bad catalytic converters. The new motor showed up at my house tonight and I figured it was easiest to do everything at once with the motor out. Defiantly doing a cat back exhaust system but I have a question on if this means they include cats or do I have to buy them separate? Also debating on headers. What exhaust and cats do you guys recomend? Is it worth it to do an intake too? If I do an intake do I need a tuner? Are headers worth it? And should I do duals or a single exhaust? Honestly im more into the sound then the power increase but I'll never say no to a faster truck and I like the sound of the magnaflow but are there better options out there? Im only 16 (if im allowed to tell you that, it said I had to be 18 to register) and close to all my money is going into this truck so I want to make sure im making the right decision. Thanks in advance

 

Sorry for the long post btw

 

If you have money to spend why not? Aftermarket cats dont last as long as OEM. if you get headers, get stainless. Cat back, whatever. Id probably run duals, with tail pipes, but thats me. With 290k, better look at your axles, front end, and transfer case... (if its 4x4)

 

I replaced both of my cat assemblies with Magnaflows which are very good quality. Nearly identacle to OEM. The left bank was almost completely clogged on mine. I also replaced the O2 sensors.

 

The transfer case works great, im getting a front end alignment soon and I'll have to look into the axle... And I don't have all that much money to spend haha every penny i make goes into this truck that's why I wanted to know if headers were actually worth the money with there performance gains