i have a 95 f150 5.0L. I'm thinking about cutting off all cats, and buying a high flow race cat and running just a single pipe, maybe the same but instead of cat a cherry bomb, or maybe no cats and a cherry bomb extreme single in dual out and running duals. probably gonna try to keep 2.25" or maybe go up to 2.5". Definitely have a small budget.

 

Hey man either way sounds like a good bet. On my 90 F150 I have the 5.0 as well, and what I saw the best gains with was long tube headers into a custom y-pipe that's 2.25 inch. That transfers into a single 3 inch pipe with a high flow cat ending with a Flowmaster 44 and dumped before the axle. The only reason I run a cat is for emissions. This setup is loud and still provides a decent dose of backpressure, and definitely improved power in the entire rpm range. The most expensive part was the custom y-pipe but even then I was able to stay under $300 with headers included.

 

Which would be the least, well, illegal? Cherry bomb or high flow cat? Dont wanna be getting pulled over.

 

Honestly, I would do a Single STAINLESS cat back system. It will be a lil bit more money, buy you will not have to do it all over again in 1-2 years

 

Stainless is a definite with me. I will never put another plain steel system on a vehicle. I plan on building my own.

 

JUst a FYI, stainless pipe is EXPENSIVE. I just spent 100 on a 4' length of 2.25 and a stainless turndown. You can buy complete(hangers, clamps, etc) cat back system for about 350

 

Unless your cat is clogged or the material is broken down, there is no reason to replace the cat. Modern cats do not restrict flow like the early ones in the 70's and 80's did. If your truck is OBD II you may also run into problems with a check engine light by removing the cat. As mentioned, I'd go for a stainless cat back system. The only reason I took mine out was because the case was leaking.

 

They cause alit of restricting back pressure, and dampen alot if sound. Obd ii started in 96 And there is only one o2 sensor on my truck; before the cats. Plus i want put headers on due to a manifold leak. So i might as well redo the entire system.

 

Go for a single high-flow cat then if you're rebuilding the entire system. Depending on what kind of muffler you go with it could mean the difference between sounding good and having a lot of drone (flowmaster).

FWIW, I'd like to see someone compile real data (backpressure readings taken upstream) regarding the "huge backpressure" cats generate. Unless it's a poorly designed one with a bend in the case (like the Explorers) or a 90* outlet (SHO), then there shouldn't be a problem. Not picking on you personally, it's just that I've seen a lot of threads where people insist that they're losing power (according to their butt dyno) due to a convertor.

 

I'd have to agree on that backpressure theory. Personally when I welded the cat into the exhaust system there was no noticeable power loss or sound loss for that matter once I drove it. In the process of taking the section of pipe out it was just a y-pipe into a foot of a 3 inch diameter section, and I may or may not have ran that a couple miles. Talk about a loss of power!

I looked at my muffler today and it's a flowmaster 44 which personally I'm not a fan of the loud raspy sound they have on other vehicles but on my truck it sounds pretty damn mean with no drone on the highway I'll try and get a video if I can this week