So I need to replace my cats. It's a '97 f-150, 4.6, 200k.

I don't want to replace each side with entirely new cat/pipe combos, which run about $250 each.
However, I'd like to just splice in Magnaflow cats from Troyer.
One cat apparently replaces the two, which is a whole lot nicer ($84).
See em here:

http://www.troyerperformance.com/cgi...atalogno=54304

My question is: has anyone done this before?

I don't have a problem with the welding, just the theory behind it all.

I'm going to have to save the flange which connects to the manifold, and then I was maybe thinking of some stainless flex pipe to replace where the first old cat was?

Does this sound wrong to anyone?

Suggestions please!

I should also note that I would also be replacing the two rear 02 sensors, and only plan on having this truck for another 6-8 months.

Much obliged

 

Check your state emission/inspection policies before you do the work, I've seen multiple posts by people stating they failed inspection for only having the 2 hi flow maggies, they still want to see the pre cats under there. I will have to change mine soon and I plan to gut the precats and relpace the cats with the high flow magaflow cats.

 

i dont recomend flex pipe. cut out the section after the first o2 sensor then before the second one. right before the pre-cat and right after the cat. id have a shop bend a 2.5 inch pipe that you could weld in yourself. i would stick the cat on the cut you made before the rear sensor. then measure up to the cut near the manifold to the top of the maggie. this is what the shop would have to fabricate, its not that hard, the only tricky part is the angle. they should be experts and able to do it quickly. i have the high flow maggies with the 4.6 and have had no problems with about 20k. no CEL and like the sound difference, more crisp.
many people here have done the same thing on this site.

 

i dont recomend flex pipe. cut out the section after the first o2 sensor then before the second one. right before the pre-cat and right after the cat. id have a shop bend a 2.5 inch pipe that you could weld in yourself. i would stick the cat on the cut you made before the rear sensor. then measure up to the cut near the manifold to the top of the maggie. this is what the shop would have to fabricate, section of pipe. its not that hard, the only tricky part is the angle. they should be experts and able to do it quickly. i have the high flow maggies with the 4.6 and have had no problems with about 20k. no CEL and like the sound difference, more crisp.
many people here have done the same thing on this site. flex pipe sucks, stay away from it