KYOSTAR Catless Downpipe for 2015-2020 BMW F80 M3 F82 F83 M4 F87 M2 Competition S55 3.0T The KYOSTAR Catless Downpipe is designed for BMW S55 3.0T twin-turbo engines, including F80 M3, F82/F83 M4, and F87 M2 Competition models. This performance exhaust upgrade replaces the restrictive factory catalytic converter section to improve exhaust gas flow, reduce backpressure, and enhance turbocharger efficiency for BMW M enthusiasts seeking improved engine response and performance.