Milltek Secondary Cat Bypass | BMW G8X M3 M4

Description

102mm single mid pipe non-resonated X pipe secondary catalyst bypass for BMW G8X M3 and M4. Bolts directly to OE axle back (SSXBM1342) or Milltek axle back exhaust (SSXBM1341). Track-focused configuration eliminates secondary catalyst restriction while maintaining OEM+ fitment and hanger compatibility. Hand-finished T304L stainless steel construction with mandrel-bent piping. Non-resonated design optimized for closed-course and track use. Dyno-proven power gains with engineered tone character across the RPM range. • Fits BMW G8X M3 (S58 engine) and M4 (S58 engine) • Direct bolt-on to OE or Milltek axle back systems • Uses factory hangers and mounting points — no modification required • T304L stainless steel, hand-finished • Mandrel-bent X pipe configuration • Track/closed-course optimized — non-resonated • Valve-compatible for OE secondary valve functionality In-house manufacturing from raw stainless steel to finished component ensures precision fit and durability. Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Fits 14 vehicles including:

• 2021 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2022 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2023 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2024 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2025 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2026 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• + 8 more vehicles