Stainless Steel Exhaust System | BMW M340i/M440i

▶ Hear this exhaust 0:00 Open audio .cb-audio-widget{display:flex;align-items:center;gap:.6rem;flex-wrap:wrap} .cb-audio-play{background:#e1122f;color:#fff;border:0;border-radius:8px;padding:.5rem .75rem;font:600 14px/1.2 system-ui;cursor:pointer} .cb-audio-play[disabled]{opacity:.6;cursor:not-allowed} .cb-audio-seek{flex:1;min-width:150px} .cb-audio-time{min-width:42px;text-align:right;font:500 13px/1.2 system-ui;color:#ddd} .cb-audio-fallback{font:500 13px/1.2 system-ui} .cb-audio-widget{ display:flex; align-items:center; gap:10px; font: 14px/1.2 system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif; border:1px solid #e5e7eb; border-radius:10px; padding:8px 10px; max-width:520px; height:64px; box-sizing:border-box; background:#fff; } .cb-audio-play{ flex:0 0 auto; cursor:pointer; border:0; border-radius:999px; padding:8px 12px; background:#000; color:#fff; font-weight:600; } .cb-audio-seek{ -webkit-appearance:none; appearance:none; width:100%; height:6px; background:#eee; border-radius:999px; outline:none; } .cb-audio-seek::-webkit-slider-thumb{ -webkit-appearance:none; appearance:none; width:14px; height:14px; border-radius:50%; background:#000; cursor:pointer; margin-top:-4px; } .cb-audio-seek::-moz-range-thumb{ width:14px; height:14px; border:none; border-radius:50%; background:#000; cursor:pointer; } .cb-audio-time{ flex:0 0 auto; min-width:42px; text-align:right; color:#374151; } .cb-audio-fallback{ margin-left:auto; font-size:12px; color:#6b7280; text-decoration:underline; } /* Optional: dark mode-friendly */ @media (prefers-color-scheme: dark){ .cb-audio-widget{ background:#0b0b0b; border-color:#1f2937; } .cb-audio-seek{ background:#1f2937; } .cb-audio-time{ color:#9ca3af; } .cb-audio-fallback{ color:#9ca3af; } } CarBahn Stainless Steel High-Flow Exhaust System – BMW M340i / M440i (Cat-Back) Unlock the full potential of your BMW M340i or M440i with the CarBahn Stainless Steel High-Flow Exhaust System — a true cat-back upgrade engineered to deliver the ideal mix of motorsport character and daily-driver refinement. Designed and specified by Steve Dinan and the CarBahn engineering team, this system reflects decades of tuning experience and an uncompromising commitment to OEM-level quality. Crafted entirely from corrosion-resistant 304 stainless steel with a clean brushed finish , the CarBahn exhaust is built to withstand years of heat cycles, weather exposure, and hard driving without rusting or discoloration. Unlike basic axle-back muffler swaps, this is a complete cat-back system engineered to improve exhaust flow, reduce backpressure, and bring out the true sound and responsiveness of BMW’s turbocharged inline-six. The result is a deep, powerful exhaust note that wakes up under throttle — aggressive when you want it, composed when you don’t. Cruising remains smooth and drone-free, making this system just as rewarding on a road trip as it is on a backroad pull. Engineered Fitment — Not Generic Overseas Hardware CarBahn systems aren’t mass-produced, one-size-fits-all imports. This exhaust is built to CarBahn-specified design standards , offering superior fitment and consistency compared to many overseas alternatives. Every detail is engineered for a tight, precise installation — from the alignment to the sealing surfaces — ensuring the system performs like an OEM component, not an aftermarket compromise. Premium Hardware and Quiet Precision Key upgrades include OEM-quality clamps and an advanced exhaust flapper valve design that uses a high-tech anti-rattle spring , dramatically reducing unwanted noise and vibration. The system also incorporates a joggle-slot connection , improving sealing at the joints and preventing the small leaks that can plague lower-quality exhaust setups. Key Features: CarBahn-specified design , engineered by Steve Dinan for the B58 platform Full stainless steel cat-back construction — not just mufflers — for real performance improvement Brushed 304 stainless finish for long-term durability and premium appearance Improved fitment and quality compared to overseas-manufactured alternatives Joggle-slot joint design for superior sealing and connection integrity OEM-quality clamps for factory-level installation and longevity Upgraded exhaust flapper valve with anti-rattle spring technology for reduced noise Aggressive yet refined sound with zero drone during highway cruising Direct bolt-on fitment for BMW M340i and M440i models 2-year unlimited mileage parts warranty USA-based support from the CarBahn team Elevate your BMW’s sound, performance, and character with an exhaust system designed to do more than just turn heads — it’s engineered to make every drive feel sharper, louder, and more alive… the way Steve Dinan intended.