[mike@x-ph.com]

The most popular downpipe just got even better! You now have the option to choose between the premium GESI catalytic converters or the more affordable Active Autowerke cats. Both options come with the same no Check Engine Light (CEL) guarantee and comprehensive warranty.



Active Autowerke B58 Catted Downpipe – Unleash Your BMW's True Potential
Enhance your BMW's performance and sound with the Active Autowerke B58 Catted Downpipe.

Key Features:
High-Flow Active Autowerke Catalytic Converter

Engineered to maximize exhaust flow while reducing emissions.
Guarantees no Check Engine Light (CEL) issues.
Comes with Active Autowerke's exclusive warranty for peace of mind.
Stainless Steel Construction

Made from premium 304 stainless steel for durability and corrosion resistance.
Precision TIG-welded for strength and longevity.
Optimized Performance

Increases horsepower and torque by reducing exhaust backpressure.
Enhances turbo spool and throttle response for a more exhilarating drive.
Improved Exhaust Note

Delivers a more aggressive and sporty sound without excessive cabin drone.
Direct Bolt-On Installation

Designed for a seamless fit with OEM mounting points.
Includes all necessary hardware and gaskets for a hassle-free installation.

Why Choose the Active Autowerke B58 Catted Downpipe?
Upgrade your BMW's exhaust system with confidence. The Active Autowerke catted downpipe is specifically designed for B58 engines, ensuring optimal compatibility and performance. Unlike other downpipes that use generic catalytic converters, this model features Active Autowerke's proprietary cat, which is engineered to prevent CEL issues while delivering maximum flow.

Compatibility:
BMW Models Equipped with the B58 Engine:
2 Series: M240i, M240i xDrive
3 Series: 340i, 340i xDrive
4 Series: 440i, 440i xDrive
5 Series: 540i, 540i xDrive
Z4 M40i
Toyota Supra (A90)

Active Autowerke Warranty:
Rest assured with Active Autowerke's warranty on the catalytic converter. Their commitment to quality ensures that you're getting a product that not only boosts performance but is also built to last.

Unlock Hidden Power Today
Don't let the factory downpipe hold back your BMW's true capabilities. Upgrade to the Active Autowerke B58 Catted Downpipe and experience significant gains in power, sound, and overall driving enjoyment.

[BandwidthBandanna]

I think i'd just opt for the GESI Version seeing the price difference is about $285 between the 2. (unless I looked at the wrong product). Or am I missing something?

[mike@x-ph.com]

Originally Posted by BandwidthBandanna

I think i'd just opt for the GESI Version seeing the price difference is about $285 between the 2. (unless I looked at the wrong product). Or am I missing something?

Yes, you are correct; there is a $285 price difference between the 2.

We offer and would be more than happy to sell you the more expensive option, but given that they have the same warranty and guarantee and are offered by the same company, I dont see why you would want to choose the more expensive one

[dustwhyn]

Kinda getting sick of my catless car but I’m worried about pairing this with my Pure900. I’m sure the new AA cat is a lot less restrictive than the GESi one but I’m definitely on the fence. I’ve currently got a VRSF catless and I’m tired of the smell.

[mike@x-ph.com]

Originally Posted by dustwhyn

Kinda getting sick of my catless car but I’m worried about pairing this with my Pure900. I’m sure the new AA cat is a lot less restrictive than the GESi one but I’m definitely on the fence. I’ve currently got a VRSF catless and I’m tired of the smell.

these cats are rated at 1050 whp so it should not be a problem with your setup.
the no fuel smell upgrade is on its own worth it, especially if this is your daily driver.

[dustwhyn]

Originally Posted by mike@x-ph.com

these cats are rated at 1050 whp so it should not be a problem with your setup.
the no fuel smell upgrade is on its own worth it, especially if this is your daily driver.

That’s very reassuring to know that they have such a high horsepower rating and AA has a lifetime warranty on them. I guess it’s gonna have to be next on the list because it is my daily and I can’t take the smell much longer.

[prostcfc]

Originally Posted by dustwhyn

That’s very reassuring to know that they have such a high horsepower rating and AA has a lifetime warranty on them. I guess it’s gonna have to be next on the list because it is my daily and I can’t take the smell much longer.

Small caveat, but it's not a lifetime warranty: "Covered by 5 Year / 50,000 Mile Warranty (on shell and tube ends) and 2 year / 25,000 Mile Warranty on the Catalytic core to original purchaser only - NOTE: warranty will be null and void if your car has excessive burble (greater than stock) as that physically destroys the catalytic core"

It's a great product; I have it myself. But if I start getting CELs this Christmas, I'm out of luck.

[dustwhyn]

Originally Posted by prostcfc

Small caveat, but it's not a lifetime warranty: "Covered by 5 Year / 50,000 Mile Warranty (on shell and tube ends) and 2 year / 25,000 Mile Warranty on the Catalytic core to original purchaser only - NOTE: warranty will be null and void if your car has excessive burble (greater than stock) as that physically destroys the catalytic core"

It's a great product; I have it myself. But if I start getting CELs this Christmas, I'm out of luck.

Oh that’s a bummer. I’m not sure where I got the idea that it was a lifetime warranty. I don’t run any burbles at all so I’m not too worried about damaging the cat. My concern is longevity at high horsepower levels.

[mike@x-ph.com]

i dont think anyone gives a lifetime warranty on cats, not even BMW.

Cats will eventually fail, but they will outlast your car ownership in most cases.

If you dont run aggressive burble, the cats should last a long time, and warranty will not be an issue. You might need to replace the cats in a few years if you run aggressive burbles.

[Seer501]

I can verify no CEL on my M440i, but it’s important to follow the break in sheet accompanying the product!!

[mondayze]

Originally Posted by Seer501

I can verify no CEL on my M440i, but it’s important to follow the break in sheet accompanying the product!!

can you relay the info, first time hearing about a break in for a downpipe...

[Rdurty2]

Originally Posted by Seer501

I can verify no CEL on my M440i, but it’s important to follow the break in sheet accompanying the product!!

I never did any break in and haven’t had a cel in the entire time I’ve had the downpipe, over 2 years now.

If a break in was required then AA would most likely put that on a piece of paper with each downpipe shipped or on their website with the product listing, but they don’t.

[Seer501]

They did put a break in sheet in the box with my AA pipe.

[Seer501]

I threw the sheet away after install. The install sheet was included in the box with the pipe. Search across the forum and you will see others that have ordered state the same thing.

[Seer501]

From another forum….I had an install sheet in my box. I would recommend following the instructions…. For no CEL.

[CBO]

Is the gesi cat more restrictive than the regular 400 cell they use? I know both are better than stock, but will one make more power than the other?

[Rdurty2]

Originally Posted by Seer501

They did put a break in sheet in the box with my AA pipe.

Odd, mine never came with one and haven’t had a single cel in over 2 years so the break in can’t be that important.

[mike@x-ph.com]

Originally Posted by CBO

Is the gesi cat more restrictive than the regular 400 cell they use? I know both are better than stock, but will one make more power than the other?

its not, GESI cats are rated for 850 whp
99% of application are not going near that kind of power

Originally Posted by Rdurty2

Odd, mine never came with one and haven’t had a single cel in over 2 years so the break in can’t be that important.

when i purchased my downpipe, they did not include a break in sheet, and i have had it on my car for 5 years no CEL

[Seer501]

As stated, my AA cartted downpipe came with an instruction sheet stating what I copied & pasted above. They didn’t put it in the box for decorations. Obviously the mfg had a reason for the instructions & based on the verbiage, it simply looks like an easy “warm-up / break in” for the pipe at low RPM’s. I don’t have the slightest idea as to why some got instructions & some didn’t. Common sense…if you receive a part & it comes with instructions, use the instructions. Why wouldn’t you.

[mike@x-ph.com]

Originally Posted by Seer501

As stated, my AA cartted downpipe came with an instruction sheet stating what I copied & pasted above. They didn’t put it in the box for decorations. Obviously the mfg had a reason for the instructions & based on the verbiage, it simply looks like an easy “warm-up / break in” for the pipe at low RPM’s. I don’t have the slightest idea as to why some got instructions & some didn’t. Common sense…if you receive a part & it comes with instructions, use the instructions. Why wouldn’t you.

i think they started doing it after some downpipes got the CEL. I believe all the new shipments come with break-in instructions.

[ChrisWMT]

Any word on compatibility/CEL on 2025's with OPF's?

[mike@x-ph.com]

Originally Posted by ChrisWMT

Any word on compatibility/CEL on 2025's with OPF's?

im not very familiar with OPF but it was my understanding that this sensor is in the midpipe, not the downpipe