So I've been following the forums and talks on headers and such, and what I'm hoping for here is some sort of final verdict on the issues of using a cat, or not using one.

I understand I can use a defowler for my o2 sensor to keep from throwing codes if I use a test pipe. But, I'd still like to try and be kind to the environment and use a cat. Now, I don't want to cut up my OEM headers for the cat, in case I need them for whatever in the future.

So, can I get a count / consensus on what aftermarket cats have held up? Will the exhaust be super loud without one (meaning way more so than with a cat, I know headers will be loud anyway, just don't know how much louder than normal headers if theres no cat).

And finally, anyone have an OEM cat they have laying around, or can cut off some old OEM headers they would care to donate, or sell cheap, or trade for Some other OEM parts I have?

Thanks guys!

 

what header are you gunna get cause im interested in doing the same thing, i was thinking of the OBX header with the stock cat welded back on

 

In what manner will you be using the car? Track only? Street/hwy only? Combination of some track/street/hwy? Makes a big difference in what set-up to get.

 

not too many tracks around me, so mostly street use and highway once in a while

 

I can't comment on a specific header since I just bought my Mini and it has a header with a stock cat welded in but here is what I can tell from years of experience with other cars (N/A and forced induction).

You really only want to remove the cat completely if you are looking for every last ounce of power. Although no cat will be louder, the amount of "sound" you want from the exhaust on a street car can easily be dictated by choice of catback exhaust and keeping some cat, from my perspective, is good all around.

A high flow cat will be a bit louder with "amount" being slightly different based on the type/quality of the construction of the cat. Oh and although I have not changed the exhaust manifold yet, my guess is that it is not the easiest thing to do so go with the highest quality cat you can afford (saves hassle/money in the long run).

 

Turns out I've got supersprint headers! (didn't get to see them till just the other day)

My car is a street only car, no tracks around, so "every ounce of power" isn't really necessary, but I do want to keep a tight and low budget if possible.

Still trying to find an OEM header I can chop up, one that isn't mine.

I thought about getting the supersprint test pipe, which is about $200 after shipping (I think), but I'm wondering if something else couldn't be made for less? Id get the SS cat, but it's like $1200 , which is just silly.

I've also found universal resonators online for cheap, thought I could use one of those to lesson the sound if I go cat-less?
Can anyone tell me how Long their connecting cat / test pipe is please?

 

catless is going to sound sick, just wait for your burble

 

If I got a magma flow universal high flow cat, what size should I be looking at?
Thought I read 2.5" somewhere...

 

what ever the head pipe is in diam i think you would be safe with for the cat

 

My Mynes V.1 headers + cat is still well, 4 or 5 years now? No tracks but some few hard runs when street/ Hi-way is safe. I also have the O2 spacer (anti-fouler) prior to install.
I read in UK forums that they re-weld the OEM cat on Janspeed Headers with good success and still gain HP/Tq. Some headers may not allow this due to design and space constraint.

 

What about this thing? Looks solid I guess.
Or is this a buy cheap buy twice thing?

http://www.ebay.com/itm/2-5-Thunderbolt-Spun-Metal-High-Flow-Performance-Catalytic-Converter-New-/170783407749?pt=Motors_Car_Truck_Parts_Accessories&hash=item27c37bfe85&vxp=mtr

 

I just had an OBX header put on mine with the stock cat welded on. NO lights and no problems so far. I haven't really run it hard yet but it sounds great!

 

The mini has one header, not headerS