MAD BMW M3 M4 S58 G8x Single Midpipe TitaniumUpgrade your BMW M3 M4 S58 G80 G82 G83 with the MAD Single Midpipe Titanium, designed to deliver superior sound and performance by eliminating unnecessary restrictions. Key Features: Resonator and Secondary Catalytic Converter Delete: The MAD Single Midpipe removes the two resonators and two secondary catalytic converters found in the stock midpipe. The primary catalytic converters in the downpipe remain untouched, ensuring no check engine light (CEL)