BMW 1 Series (F20/F21) Catless Downpipe – High-Flow Stainless Steel Design for Enhanced Turbo Response & Performance | Fits 118i, 120i & 125i Hatchback Models – B46 2.0L Turbo Engine (2016–2019)

Unlock the full performance potential of your BMW 1 Series (F20/F21) with the BAVMODS® Catless Downpipe — precision-engineered for the B46 2.0L TwinPower Turbo engine to improve exhaust flow, enhance turbo spool, and unleash a deeper, more aggressive tone.

The factory catalytic converter on BMW’s B46 engine is highly restrictive, trapping heat and creating unwanted backpressure that limits horsepower and response. The BAVMODS® Catless Downpipe removes that restriction entirely — allowing your turbo to breathe freely and perform the way it was truly designed to.

Engineered for the B46 Power Platform

Constructed from high-grade T304 stainless steel, each downpipe is TIG-welded by hand and mandrel-bent to ensure the smoothest internal flow path possible. Every unit features pre-welded O₂ sensor ports, mounting flanges in factory positions, and an integrated heat shield section to reduce radiant heat in the engine bay and protect nearby components.

Key Performance Benefits

• Free-Flow Straight-Pipe Design: Removes the restrictive factory catalyst for maximum exhaust velocity.
• Improved Throttle Response: Reduces backpressure, allowing boost to build faster and hold longer.
• Dyno-Proven Gains: Expect noticeable increases in horsepower and torque when paired with a proper Stage 2 ECU tune.
• Aggressive Exhaust Tone: Deep, clean turbo note with a sharper, motorsport-inspired character.
• Thermal Efficiency: Stainless construction and heat shielding reduce exhaust gas temperatures and improve reliability.
• OEM+ Fitment: Direct bolt-on installation compatible with both factory and aftermarket exhaust sections.

Installation & Compatibility

Each downpipe kit includes premium gaskets, clamps, and hardware for a complete bolt-on installation — no cutting, welding, or modification required. Pair with a Stage 2 ECU tune for full CEL management and maximum performance gains.

Performance You Can Feel

From the first throttle input to redline, the BAVMODS® Catless Downpipe delivers sharper boost response, quicker acceleration, and a bold, resonant tone that brings out the true character of your B46 engine.

FITMENT: BMW 1 Series (F20 5-Door / F21 3-Door) – 118i, 120i, 125i (2016–2019)

ENGINE COMPATIBILITY: B46 2.0L TwinPower Turbo Inline-Four

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