2nd cat delete
 

Hey guys just looking for opinions would you cut it out and put s new pipe in or take it off and beat the inside guts out and bolt back in for a factory look?

Depends on what you want to do. are you doing the work? or are you paying someone? Does your state have inspections?

Also, I'm pretty sure there is a million posts about this. Google is your friend.

Just cut it out, weld a straight pipe in. Much easier.

it's post sensor so you'll need to check with your local emissions laws with regard to whether they perform visual inspections or not. it's a solid mini-mod tho and super easy to throw back in the stocker should you choose to get an aftermarket pipe. ultimate racing offers one with a resonator option which actually maintains a stockish look. you can't reuse their gasket tho. a bunch of options out there. but yeah, make with the google and you'll find a wealth of info on this subject, specific to our platform. and remember, only you can prevent forest fires.

I'll be doing the work and Im in Canada NS no emissions
I feel like taking the guts would be better as it would look cleaner if ever hoisted for a visual inspection of the underbody instead of a cut up welded exhaust

Just buy a turbo back with no cats. Problem solved :)

Full turbo back is an expensive waste on the stock KO4. You can't push enough flow through the K04 to benefit from the 3" CBE part. The restrictions, and they are severe, are in the stock d/p and the two cat.

OP can pick up a little power with an aftermarket race pipe in place of his secondary cat. They are cheap, and he can keep his old secondary cat to go back to stock when it comes time to sell.

For full power flow on the K04, a 3" catless dp and rp into the stock CBE is just as effective as a turbo back. By the time the exhaust from the turbo impeller passes through the dp and rp they have cooled and compressed back enough to be unrestricted by the stock CBE.

Just buy a racepipe and bolt it on. That's about as clean and simple as it gets.

http://www.mazdaspeedforums.org/foru...d.php?t=165657

Check this out, may help you make up your mind with facts instead of opinions.

This is a very simple cheap mod, easy to do and good hp per dollar spent.

If the OP searched, he would of found a plethora of options that are tried and true. He also seemed to have the answer to his own question being that he was going to gut the cat so it looks stock.

TLDR; get race pipe, /thread

If OP donated he could buy said RP for $100.

Well knocking out the honeycomb is free, hard to beat free. That's what I did. Then 2 months later I blew engine #1 because I didn't upgrade my HPFP internals....LOL

Hey neighbour. Get fuel pump internals. AP. 3 inch intake . Test pipe. Rear motor mount. Tune. Then intercooler then dp, then meth , retune. Blow doors

Dp doesn't matter much with the test pipe. E85 is where its at for power - I've been doing 50/50 mix and get stupid amounts of power from it. Corn tune is hands down the biggest bang for the buck.