The Milltek Full System Exhaust with Cat Replacement Pipe for the BMW 3 Series E30 M3 (1987–1992) is a high-performance stainless steel exhaust system designed to enhance engine sound, reduce back pressure, and increase horsepower.It replaces the factory catalytic converter and includes all necessary components for improved exhaust flow and sporty driving performance. Ideal for enthusiasts seeking a more aggressive tone and better throttle response.