BMW G20/G21 M340i Valved Cat-Back Exhaust System – Sedan & Touring (SWB, RWD / xDrive) | Select Quiet or Loud Sound, Premium Performance Upgrade

From the factory, the G20 / G21 exhaust system is heavily restricted and tuned for compliance, muting the natural tone of the turbocharged four- and six-cylinder engines. The BAVMODS® Valved Cat-Back corrects this with a straight-through, mandrel-bent flow path and valve-controlled sound modulation, allowing exhaust gases to exit more freely and evenly.

When the valves are closed, the system channels exhaust through a resonated path for a smooth, subtle tone ideal for daily driving.

Open the valves, and the exhaust bypasses the resonator — unleashing a raw, aggressive growl with sharper turbo spool acoustics and enhanced overrun burbles.

The result is a dual-character system — refined when you need it, thrilling when you want it.

Crafted from Premium Materials

Each system is built from stainless steel for exceptional corrosion resistance and longevity. Every section is mandrel-bent and TIG-welded to ensure flawless internal smoothness and precise alignment with factory mounting points.

The internal muffler design equalizes backpressure and minimizes turbulence, promoting faster turbo response and consistent power delivery throughout the RPM range.

Key Features & Benefits

• Valved Dual-Mode Sound Control – Instantly switch between quiet cruising and open-valve aggression.
• Mandrel-Bent Stainless Construction – Maximum durability and heat resistance.
• Enhanced Flow Efficiency – Reduces backpressure, improving turbo spool and mid-range torque.
• Aggressive Yet Refined Acoustics – Deep, balanced tone without excessive drone.
• Plug-and-Play Fitment – Direct bolt-on design compatible with stock downpipes and factory mounts.
• Higher Horsepower Potential – Optimized for increased exhaust velocity and reduced restriction.
• OEM+ Finish – Mirror-polished tips and clean welds that complement the rear valence.

Included Components

• Complete valved cat-back exhaust assembly (mid-pipe + rear muffler)
• Dual polished exhaust tips
• Vacuum valve control system (Quiet / Loud toggle switch)
• All required mounting hardware and clamps

Performance & Sound You Can Feel

The BAVMODS® Valved Cat-Back Exhaust System offers the perfect balance between sophistication and performance.

With the valves closed, enjoy a composed factory-like hum; open them, and experience an exhilarating symphony of turbocharged precision.

Expect:

• Sharper throttle response
• Deeper tone under load
• Crisp overrun pops and burbles
• Noticeably freer mid-range pull

It’s the ultimate OEM+ upgrade — purposeful sound, elevated performance, and a factory-fit finish.

FITMENT: BMW 3 Series – G20 / G21 (2019–Present): G20 – Sedan (SWB, RWD & xDrive), G21 – Touring (Wagon, RWD & xDrive) M340i Models.

IMPORTANT NOTE: All exhaust systems are custom fabricated to order. These are not generic third-party exhausts — our team handles each system in-house, and you’ll be able to see the craftsmanship immediately upon unboxing.

While materials are sourced worldwide, all final metalwork, quality assurance testing, and fitment/mounting verification are completed at our facility in Texas, United States.

Because of the extensive labor involved and the high cost/risk of return shipping exhaust systems, full returns are not accepted. However, if there is ever a verified fitment issue, we will 100% stand by our guarantee and, with proper documentation, make sure you are taken care of.

Please note: once an order is placed, if we are not contacted within 24–48 hours of order placement, cancellations cannot be promised.

Each exhaust unit takes approximately 2–3 weeks for full fabrication. Once fabrication is complete and the system is in quality assurance testing, we will send detailed photos of your exhaust for you to review and approve so you feel fully confident before it ships.

Please refer to the “Fitment” section in the product description for compatibility details.