3.5" High-Flow Cat

The CTS Turbo 3.5″ High-Flow CAT is engineered to maximize exhaust flow for the BMW N55 engine equipped with a pneumatic wastegate, aiming to significantly enhance power gains beyond factory specifications. This component replaces the restrictive OEM downpipe, unleashing the potential of your BMW's performance. Constructed from durable T304 stainless steel, this high-flow catalytic converter features hand TIG welding and back-purging for exceptional longevity and reliable performance. Its design utilizes the latest CAD technology to ensure a perfect fit in place of the factory downpipe, offering both uncompromising performance and a refined exhaust note – sporty when accelerating, yet subtle and drone-free during cruising. It is crucial to note that this product is sold for competition use only and is not legal for installation on highway or street vehicles. To prevent a Check Engine Light (CEL) from illuminating, proper tuning software is required; the use of Bootmod3 software is strongly recommended. Catalytic converters damaged by "crackle tune" modifications are not covered under warranty. This downpipe is specifically designed for the F30 BMW 335i & 335xi models produced between 2012 and 07/2013, as well as the F20/F21 BMW M135i & M135xi models from 2012 to 07/2013. For 135i or 335i models with a production date after 07/2013, a different 4″ downpipe is required.