[Yiruna]

Someone on this forum suggested removing the 2nd half (?) Of your OEM cat for increased power and better sounds. Want to know your opinion on it.

Claims to say that it has proven gains.

I'm not gonna do this btw I just want you take on it

[No Boost]

Absolutely not

[Yiruna]

Originally Posted by Stage IV

Absolutely not

Which is what we were saying, but idK man, thats just super ballsy.

[lax01]

Zero proof that it actually improves performance...and at the risk of destroying the OEM cat

Remanufactured Cat is $1200-1600

Not worth the risk to me...



I have no idea how'd take this apart to remove the rear section...and why that would improve flow enough like a 200-300 racecat...

[pz619]

It's an expensive piece of equipment to replace if you screw it up, and chances are you will. I never heard of someone gutting half a cat. Just get a downpipe with a high flow cat (fabspeed comes to mind) if you want more sound/power and still somewhat care about the environment.

[Yiruna]

Originally Posted by lax01

Zero proof that it actually improves performance...and at the risk of destroying the OEM cat

Remanufactured Cat is $1200-1600

Not worth the risk to me...



I have no idea how'd take this apart to remove the rear section...and why that would improve flow enough like a 200-300 racecat...

Seriously I don't know what information that guy in that thread was basing it off of. I've never heard ANYONE do this before

[Yiruna]

Originally Posted by pz619

It's an expensive piece of equipment to replace if you screw it up, and chances are you will. I never heard of someone gutting half a cat. Just get a downpipe with a high flow cat (fabspeed comes to mind) if you want more sound/power and still somewhat care about the environment.

Apparently I'm a noob because I don't do this, and that I'm better off doing this because Sport Cats always fail later on anyways. F**k me right?

[DETRoadster]

Originally Posted by pz619

It's an expensive piece of equipment to replace if you screw it up, and chances are you will. I never heard of someone gutting half a cat. Just get a downpipe with a high flow cat (fabspeed comes to mind) if you want more sound/power and still somewhat care about the environment.

Exactly. Get a high quality aftermarket performance cat like Fabspeed for less money than a re-manufactured OEM cat. Put your barely used OEM cat safely on the shelf in case you ever find yourself in the situation where you need to swap it back in and go back to stock. Cutting your OEM cat apart is silly. Reminds me of kids in highschool drilling out the baffles in their stock mufflers or drilling holes in the air box on their VWs.

If you can afford a $55,000 BMW you can afford to not cut corners on modifying it.

[pz619]

Originally Posted by Yiruna

Apparently I'm a noob because I don't do this, and that I'm better off doing this because Sport Cats always fail later on anyways. F**k me right?

I have the fabspeed on my car for 20k+ miles. No problems and I don't expect any in the near future.

[Yiruna]

Originally Posted by pz619

I have the fabspeed on my car for 20k+ miles. No problems and I don't expect any in the near future.

Man when I first out on the fabspeed it was so good. Worth it imo

[NO_USER_]

fuck no lol, quite possibly the dumbest “mod” HAHA

I can see how one would do this "mod" (this is how the guy preaching about this "mod" did it), if you look at your OEM downpipe, the 2nd O2 sensor is between two separate cats, there's a space between them. So, I think if you enter from the catback side of the downpipe, you can basically break apart that second cat and you'll be left with the first cat before the 2nd O2 sensor and after the 1st O2 sensor.

I think the cat this individual removed is a different cell count than the first cat between the O2 sensors. Not sure if the following cell count is correct, but the cat he removed is 200 cell, leaving the 400 cell one in.

I have no idea if a CEL will show up, but theoretically it shouldn't because the 2nd O2 sensor (which checks for efficiency) is after the 1st cat.

But in NO WAY would this "mod" be equal or better than buying a 200 cell catted downpipe or of course catless. This individual also attacks other vendors that are trying to sell a proven product such as the Fabspeed Catted downpipe. I'm catless btw LOL.

No one should attempt this "mod" as others have already said, many reasons as to why it's a stupid idea.

I'm really interested if this individual is running a "stage 2" tune on his car with his gutted downpipe? Wouldn't that create a lot of extra heat and have too much back pressure than what the map is made for (most common cell count of 200 or catless)?

[Orange fever]

^ yup

[Bt12]

I wouldn’t do it...but i would cut springs tho lol


Just not on the m2.


Maybe if I was still in my rice days.


I refuse to buy products without a dyno

[Orange fever]

Circa 1997-2000 ( cutting springs)

Originally Posted by Bt12

I wouldn’t do it...but i would cut springs tho lol


Just not on the m2.


Maybe if I was still in my rice days.


I refuse to buy products without a dyno

[pz619]

So where is this thread where someone decided to gut their cat??

[Yiruna]

Originally Posted by pz619

So where is this thread where someone decided to gut their cat??

It's in the buy and sell thread for classifieds. Under the recent fabspeed one

[pz619]

Originally Posted by Yiruna

It's in the buy and sell thread for classifieds. Under the recent fabspeed one

Wow... just wow.

[DETRoadster]

Originally Posted by Orange fever

Circa 1997-2000 ( cutting springs)

Shoot, we were doing that in the '80s!

[lax01]

http://f87.bimmerpost.com/forums/sho...1457649&page=2

[six-n-twins53]

No. This is not an '83 camaro.

[Yiruna]

Originally Posted by six-n-twins53

No. This is not an '83 camaro.

Tell that to the guy in that thread lmao

[NO_USER_]

Originally Posted by brooke1972

2500 on mine with 0 issues. The sound is deeper and I can feel a bit more torque on the butt dyno. No worries when I take it in for service because the oem cat there. The aftermarkets cats offered have failure issues so research. Easy mod, save $1000. A few of us pioneers have already done this mod with Great success so sit back and watch the Trolls do what they do best.. Tehboost is worried about the venders here instead of its own members. This is really a great diy mod but the companies that sell aftermarket cats don't want people to do this because it would hurt their sales. Hey no one is twisting anyones arm here to do it. Like I said before me and a few others have already done it and speak of Facts based on what has already been done rather than an opinion of people talking about things they know nothing about. One of the best mods I have done to my m2 besides disabling the asd.. Let the haters hate..
PEACE!!!!! ><///`>

Prove it with actual data, not “butt dyno”. Compare it to a catted or catless downpipe.

I’m not worried about the vendors, I’m worried about other M2 owners falling for this “mod” which will cost them a lot more $ in the end with much less performance (if any at all).