MilltekSecondary Catalyst BypassFitment: BMW G8X M3 M4

Overview

Milltek Axle Back Secondary Catalyst Bypass system for BMW G8X M3 and M4. Direct fitment 102mm single mid-pipe with X-pipe configuration. Non-resonated design for closed-course and track use. Connects to either OE axle back (SSXBM1342) or Milltek Cat-Back Axle Back (SSXBM1341).

Mandrel-bent T304L stainless steel construction with hand-finished welds. Removes secondary catalyst restrictions post-turbocharger for improved turbo efficiency and mid-range response. Engineered to work seamlessly with both OEM and Milltek exhaust systems. Uses OE mounting points and hangers—no modification required.

Details

• Fits BMW G8X M3 (S58 engine) with OE or Milltek axle-back systems
• Fits BMW G8X M4 (S58 engine) with OE or Milltek axle-back systems
• Non-resonated: optimized for track and closed-course driving
• 102mm bore mandrel-bent X-pipe design
• T304L stainless, TUV tested for durability

Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Fitment