Upgrade from the stock N55 downpipe to the MAD N55 catless downpipe for maximum airflow, power, and sound! The Mad N55 Catless Downpipe is a high-quality aftermarket performance part designed to enhance the power and sound of your BMW. Made from premium-grade stainless steel, this downpipe is engineered to deliver maximum performance gains by optimizing exhaust flow. The removal of the catalytic converter allows for a freer flow of exhaust gases, resulting in improved turbo spool, increased horsepower and torque, and an aggressive exhaust note that will turn heads on the street or track. The Mad N55 Catless Downpipe is also designed to be a direct bolt-on replacement for your stock downpipe, making installation quick and easy. This downpipe is specifically designed for use with BMW N55 engines and is compatible with a wide range of BMW models including the 135i and 335i Additionally, the Mad N55 Catless comes with a limited lifetime warranty, ensuring that you get a reliable and durable product. Upgrade your BMW's performance and sound with the Mad N55 Catless Downpipe and experience a driving experience like no other.   Features: Smooth bends for maximum airflow without any drone Up to 30HP increase on the stock turbos, even more on upgraded turbos Lifetime warranty on defects and fitment 90 day return period All orders ship in 1-2 business days Spot on fitment Flex section Fitment: 2012-2013 M135 (Up tp 07/13 production)  2012-2013 335 Sedan (Up to 07/13 production)