Catless pipe

[TheMechanic]

HI all,

Would a catless x-pipe make the car much louder than stock on my E92 M3? Everything else kept stock?

I have good experience on my 335i removing the rear cats (slightly louder, and much better pickup, they were cracked and blocking flow inside).

Thank you

[mym3adventures]

Yes. Removing restrictions will increase volume, especially cats.

[Nairb1]

It’s hard to describe sound levels but…
I have test pipes with stock muffler only removing the front cats.
The sound level is half a step louder than stock. Just less than most cat back exhausts with cats. Just about perfect in my opinion.
I imagine a catless x pipe would be similar sound level.

Lots of videos with comparisons to listen to.

[iamtrashman]

https://youtu.be/BFf5H2ygMcE

This is a quad resonated catless x pipe on mine. It is quiet when just putting around but it is still very loud under WOT.

[Bmwdeven]

Sound clip driving:

RPI mid pipes
RPI Axle back
No no cats

https://youtu.be/nq6MyBqpTAc?si=eyq3H4_6UfokdNWo

[Reddevils7]

I just have the active Autowerk Catless X pipe on mine, everything else is stock. It deleted the primary and secondary cats but retained a pair of resonators like stock. It's definitely louder but not annoying loud. When you're driving civil it's like stock. Only above like 4k does it actually get loud loud but imo it's a necessary mod to actually let this engine breathe and come to life

[krudmunk]

I have a high flow cat with quad resonators valved exhaust setup. It's pretty loud with valves open. But it's also dependent on how much you hit the gas. It screams full throttle. But I still love how it sounds.

I imagine a full catless setup to be bit louder. But you should keep in mind how much the exhaust gas stinks. I have high flow cats but it is pretty strong. S65 stinks but sounds good tho lol

[spammysammich]

I hate the smell and the attention from every flat bill that sees the car. I’m saving for an x pipe with cats in the secondary position. I don’t care if it loses a couple horsepower, 400 is more than I’ve ever had and can handle.

[TheMechanic]

so... looking at it; the stock has front cats (after headers), rear cats (part of xpipe) and resonators (part of xpipe). Right ?

How much does the sound change with just xpipe and resonators like the Autowerks one, but keeping the front cats and rear end stock ... and does it throw a code if you remove the rear cats?


Thanks!