Stainless Steel Exhaust System | BMW M340i/M440i

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.

Orders are processed same or next business day. Shipping times vary depending on the product, shipping service, and whether freight shipping is required. While we ensure all inventory levels are current and accurate, they can change due to logistics and inventory feeds. Standard shipping typically takes 3-7 business days, but some items may require additional time depending on their origin. Feel free to call us anytime for the latest status of your order.