BMW Exhaust Parts, Mufflers & Catalytic Converters for BMW 4 Series G22 (2021+)

Introducing our Turner Performance Cat-Back Exhaust for your G20 M340! Precision-crafted exhaust that elevates your driving experience with a new level of excitement. Designed with our commitment to performance and quality, this exhaust is meticulously engineered to unleash the true potential of your M340. In tandem with performance and sound, our cat-back exhaust enhances the visual aesthetic with upgraded quad exit exhaust tips that complement the overall motorsport nature of the M340 and replace the fake factory exhaust tips. Upgrade your driving experience with our cat-back exhaust for your M340! Unleash the power, bask in the glorious sound, and turn heads wherever you go.

Using our signature design principles this exhaust is crafted to deliver a deep, authoritative tone that reveals the true rowdy attitude of the M340. Designed to utilize the factory valve control our cat-back provides an exhilarating sound during acceleration without compromising the daily driving amenities. Our exhaust is manufactured of 1.25mm wall T304 stainless steel for superior durability, corrosion resistance, and aesthetics. Designed with the customer in mind it features a straightforward bolt-on installation utilizing factory slip joints and mounting locations and includes are clamps and hardware necessary for installation.

Upgrading the sound:

Our exhaust allows you to turn up the volume and let the B58TU boast its smooth and hearty exhaust tone. Let's be honest, what's the point of owning a B58 if you're not going to upgrade the exhaust? Our signature muffler design allows you to transfer the exhaust valve from your factory system directly onto your new Turner system. The Turner exhaust signature muffler design allows for two flow paths that change both tone and volume. With the vehicle in eco or comfort mode, the valves remain closed, with the closed valves the exhaust system allows the gasses to flow through the muffler toning down the volume and giving a more refined exhaust note. While in driving modes sport or sport+ the valve opens and the flow path changes to a "straight flow path" essentially turning into a straight-piped exhaust for the least amount of restriction and the most amount of B58 sound!

Upgraded aesthetics:

From the factory, the G chassis comes equipped with fake or imitation exhaust tips, our Turner exhaust allows you to remove the imitation tips from the vehicle and sport a set of 4 true exhaust tips giving that upgraded motorsport styling.

How the cat-back is designed:

To create a cat-back exhaust for this incredible vehicle the upgrade happens right at the downpipe. We replaced the factory components with our full 3.0" T304 stainless steel piping. The true 3.0" exhaust makes its way through the center and rear of the car without the center muffler or resonator to keep the flow to a maximum! With smooth mandrel bent transitions our exhaust passes perfectly under the rear subframe for a factory equivalent fit. Positioned in the rear of the car is our signature B58 muffler with beautiful inlet and outlet piping that creates the perfect exhaust tuning. Featuring relief cut slip joints and fabricated sheet metal brackets the exhaust can be fully adjusted and mounted seamlessly in the factory locations. Quad 3.5" exhaust tips are optioned to fill out the open space in the rear diffuser and complete the rear profile of the vehicle.

Features and Benefits:

Street/Motorsport inspiration
Controlled by factory valves
Compatible with factory and aftermarket downpipes (80mm)
Quad exit with true exhaust tips to replace factory facia
19 lb weight savings (Factory - 65lbs, Turner 46lbs)
Part Design:

Turner In-house designed and engineered using FARO ARM laser scanning technology and SolidWorks 3D CAD modeling for precision fitment.
T304 Stainless Material in a natural finish - 1.25mm wall thickness, back purged and TIG-welded throughout
Full 3.0" Stainless Steel Mandrel Bent Tubing
T304 Stainless Steel 12mm barbed exhaust hangers Tig-Welded in OE locations for precise fitment.​
Strategically placed slip joints provide the most adjustability to obtain perfect fitment
Kit Contents:

3.0" front exhaust section (80mm flange to connect to factory and aftermarket downpipes)
Full 3.0" lightweight free-flowing midsection for better sound, performance, and weight savings.
Valved Rear muffler
Valve extension harness
Clamps and Hardware for an OEM+ install
Optional 3.5" Exhaust Tips
Product Development:

Our G Chassis B58 Valved Catback was designed, engineered, tested, and quality inspected by our Research and Development team at Turner. Nothing but the highest level of precision and quality through leading-edge product development technology including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.

For over 30 years, Active Autowerke has been the one to turn to for high-quality BMW performance products. Committed to enhancing the performance of BMWs through the highest quality products is what Active Autowerke is all about. 

The B46 downpipes are strategically engineered to virtually eliminate the immensely restrictive characteristics of the factory downpipes – therefore reducing radiant heat and increasing performance.

Features Include

NO CEL when using this downpipe

GESI EPA registered high flow and fully OBD2 compliant

Casted upper stainless steel V-Band for precise fitment

3 inch diameter piping allows for maximum power output

Quicker turbo spool

Rated for 500 to 850 hp applications

Withstands up to 1500° F

Can reach operational efficiency within 9 seconds of startup

Easily bolts-on – no cutting or welding required

Durable construction from TIG welded 304 stainless steel

Ultra high flow 400 cell per square inch catalyst

EPA certified for use on OBD2 vehicles (1996 and newer) except in California

304 stainless steel substrate in catalytic converter is furnace braised to the mantle for outstanding durability

GESi® proprietary precious metal loading technology ensures greatly reduced emissions

Both passengers and drivers are safe from harmful emissions and noise

Precise fitment

Made in Miami, Florida

Covered by 5 Year / 50,000 Mile Warranty (on shell and tube ends)

FITMENT NOTE: For G-Chassis models (G20, G22), the cutoff build date of 08/2020 is important as cars produced after that date have a downpipe with different bracket locations. Cars with a build date of 08/2020 and earlier have the brackets in a V configuration and will need Active Autowerke p/n 11-065. Cars with a build date of 09/2020 and later have the brackets in a straight line and require Active Autowerke p/n 11-065G. If your car was built in the cutover months 08/2020 and 09/2020, please call in or email us your VIN so we can ensure you get the correct downpipe.

Want to install a downpipe on your B58 equipped BMW, but still need to pass emissions? Evolution Racewerks has the answer for you with their B58 Catted downpipe. The Evolution Racewerks Competition Series Catless Downpipes is constructed from 304 stainless steel, featuring mandrel bent piping.  These are 100% TIG welded by in house fabricators and built in the USA! 

The factory turbocharger turbine housing utilizes a V-Band flange which has been duplicated and CNC machined cut out of billet 304 stainless steel. Stainless Steel CNC machined O2 sensor and laser cut brackets are TIG welded using stainless steel rods. The O2 sensor remains positioned at the factory location. Also, since Evolution Racewerks uses a larger 4.5" pipe right after the turbocharger, turbo backpressure is significantly reduced, resulting in less exhaust turbulence and backpressure which again improves throttle response and decreasing turbo lag.