BMW 3/4 Series G20/G22 B48 Valvetronic Catback Stainless Steel Exhaust System

Engineered for BMW 3 Series G20 (Sedan, 2019+) and BMW 4 Series G22 (Coupé, 2020+) with the B48 2.0L turbo engine (320i, 330i, 420i, 430i), this Valvetronic Catback Stainless Steel Exhaust System ships with its own electronic control box and wireless remote — valve management is integrated during installation and afterward operated via the included remote. Manufactured in Europe and quality-controlled by BYC Performance, this system bolts directly to the stock mid-pipe v-band.

Tuned to the B48 turbo character, the sound is quiet and refined with the valve closed, sporty and tonal with the valve open. 90 mm twin exit tips are customer-selectable in Glossy Black Stainless, Polished Stainless, Matte Carbon Fiber, or Glossy Carbon Fiber. The exit geometry is matched to the M Sport rear diffuser cutout for plug-and-play install.

Key Features

• Included Electronic Control Box and Remote: System ships with its own valve control box and wireless remote; integrated during exhaust installation, then valve open/close is operated via the supplied remote.
• Tuned for B48 Turbo Character: Mid-pipe geometry optimized for the 2.0L 4-cylinder — drone (resonance) minimized.
• T304 Stainless Steel: Corrosion-resistant premium alloy.
• Dual-Mode Sound: Valve closed sits at OEM+ levels, valve open delivers a sporty tonal note.
• CNC-Bent Piping: Smooth internal surface, flow-optimized geometry.
• Customer-Selectable 90 mm Exit Tips: Choice of Glossy Black Stainless, Polished Stainless, Matte Carbon Fiber, or Glossy Carbon Fiber. Twin outlet, laser-welded detailing.
• OEM Hanger Compatible: Direct bolt-on fit to factory exhaust hangers — no hanger modification required.
• M Sport Diffuser Fitment: Exit tips center in the M Sport rear diffuser cutout.

Titanium vs. Stainless Steel — This Is Stainless

This product is the T304 stainless steel variant:

• T304 Stainless Steel (this product): Durable, deeper sound tone, lifetime rust-resistance, more affordable
• Titanium (separate SKU): Noticeably lighter, sharper metallic note, heat-tint finish, higher cost
• For daily driving + value: stainless preferred (this product)
• For weight reduction & premium aesthetic: titanium preferred

Valvetronic System — Sound Control by Driving Mode

The valvetronic exhaust integrates an electronic valve into the mid-pipe to deliver two sound characters:

• Valve Closed: OEM+ refined character — ideal for long drives, urban driving, and night use.
• Valve Open: Sporty tonal exhaust note — turbo whistle becomes more pronounced, drone (resonance) minimized.
• Remote Control: Open or close the valve at any time via the included wireless remote.

Vehicle Fitment

This BMW G20 G22 B48 catback exhaust fits the following engine/trim combinations perfectly:

• BMW 3 Series G20 Sedan (2019, 2020, 2021, 2022, 2023, 2024, 2025) — 320i, 330i (B48 2.0L turbo, ~255 hp 330i)
• BMW 4 Series G22 Coupé (2020, 2021, 2022, 2023, 2024, 2025) — 420i, 430i (B48 2.0L turbo)
• 318i / 330e (hybrid) B48 variants
• Compatible with M Sport bumper (Luxury Line / Sport Line bumpers use a different rear valance)
• Compatible with xDrive and sDrive trims

Incompatibility Note: This catback is NOT compatible with BMW M3 G80 / M4 G82 / M2 G87 — these cars use the S58 inline-six engine with completely different exhaust geometry, mid-pipe configuration, and hanger points. M340i/M440i/M240i with the B58 engine require a separate catback SKU (G20/G22/G42 B58 variant).

Technical Specifications

• Material: T304 Stainless Steel
• Configuration: Catback (entire exhaust from the catalyst/downpipe back to the tailpipes)
• Mid-pipe: B48 4-cylinder single-path geometry
• Valve Control: Included electronic control box + wireless remote
• Exit Tips: 90 mm twin tips — choose from Glossy Black Stainless, Polished Stainless, Matte Carbon Fiber, or Glossy Carbon Fiber
• Sound Character: Dual-mode (valve closed: OEM+, valve open: sporty tonal)
• Bumper Fitment: M Sport rear diffuser
• Origin: Europe

Installation Notes

Catback exhaust replacement requires lift access and professional installation. General procedure:

1. Lift the vehicle and loosen rear bumper underbody screws.
2. Release the stock catback mid-pipe v-band clamp.
3. Replace OEM exhaust hangers (rubber isolators) if worn.
4. Mount the included electronic control box in a suitable location and connect the valve actuator wiring.
5. Hang the new catback on hanger points and torque the v-band clamp (torque: 12 Nm).
6. Confirm the exit tips center in the M Sport diffuser cutout.
7. Pair the wireless remote and test valve open/close operation.

Care & Maintenance

T304 stainless is corrosion-resistant. Wipe polished tips with a soft cloth; avoid aggressive chemicals. If carbon fiber tips were selected, use a carbon-safe cleaner. Re-check bolt torque after first 500 km. Periodically inspect valve actuator wiring connections.

FAQ

How is the exhaust valve controlled?
Via the included electronic control box and wireless remote. The control box is mounted during installation; you then open and close the valve using the supplied remote.

How loud is it?
Calm and daily-friendly with the valve closed, noticeably fuller and more aggressive with the valve open. The B48 4-cylinder character is more tonal and daily-friendly.

Is it TÜV / E-mark approved?
The catback section does not include a catalyst, so emissions are unchanged. Qualifies for TÜV approval in most European markets.

Welded or direct bolt-on?
Direct bolt-on. V-band clamp + hanger system, no welding required.

Is it compatible with BMW M3 G80 or M4 G82?
No. M3 G80 / M4 G82 / M2 G87 use the S58 inline-six engine with completely different exhaust geometry. This catback is for B48-engined G20/G22 only.

Is it compatible with M340i or M440i?
No. M340i and M440i use the B58 inline-six engine; the G20/G22/G42 B58 catback SKU is required.

Is M Sport bumper required?
Yes. Exit tips are sized to the M Sport rear diffuser cutout. Luxury Line / Sport Line bumpers use a different valance and are not compatible.

Shipping time?
In-stock items ship within 1-3 business days via partner couriers. International shipping available.

Warranty?
BYC Performance offers a 12-month manufacturer warranty.

Why BYC Performance?

BYC Performance is a Turkey-based performance tuning specialist sourcing premium parts from leading European manufacturers and supplying them to the Turkish market. Our catalog includes BMW G20 catback exhausts, G22 B48 valvetronic systems, 330i stainless exhausts, and many more high-quality performance components. All parts are built with motorsport-grade materials and undergo strict quality control.