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.

• 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

Milltek's 40+ year heritage in precision exhaust engineering delivers measurable turbo response gains on the G8X platform—developed and validated at Nürburgring.