I've got a 2004 F250 CC 4x4 w/ the 6.0 and factory stock exhaust. I'm wanting to delete the cat & muffler to run staight-pipe exhaust. I'm looking to save $ and not buy any kits online or pay over $300 to my local exhaust shop to do the work. I've found sections of exhaust pipe, reducers, couplers, etc at the local parts store and am thinking I can do it myself with a sawsall and u-bolts/clamps. I have access to a machine to uniformly crimp the end of the pipe if needed but I can't flare them wider. I know the cat section has a bolted flange up front so I would just cut the pipe behind that for that part. Basically cut just in front and back of that and do the same for the muffler and replace those with pipe. But the cat & muffler appear to be a different size pipe. For the 2004, does anyone know what the in/out pipe diameter is for the cat and the muffler? Online resources give various sizes. I'm pretty mechanically inclined so I believe I can do this on my own. I also have access to a welding machine if I need to weld anything BEFORE it goes on the truck. Is doing it this way (shade tree style) safe and reliable? i'm on a very limited budget or else I would be more than happy to let my local small business do it.

 

Do you think you'll have any trouble with emissions testing (if they do that in your area)
You can rent from some auto parts stores a tool that will expand the end of the pipe to slip over another one.

 

Emissions aren't an issue for me in Texas. Only gassers have to do emissions testing in our county for around $40. I just do a safety inspection for $7. The guy who had it before me already had the head studs replaced, EGR delete, and relocated the cooling things. He bullet-proofed it as a preventative thing. Never had an issue, did it as a just-in-case thing. We knew him personally.

 

I have a 2002 7.3 and went too 5in down and out with no prob but check out the scm to just double check