A complete aftermarket emission and sound management solution designed specifically for the BMW E36 chassis comprises a header, catalytic converter(s), mid-pipe, and muffler. These systems replace the factory-installed components from the engine exhaust manifold to the tailpipe. Examples include cat-back systems, which replace everything from the catalytic converter backward, and turbo-back systems, which are designed for forced induction setups.
The principal advantages of such systems lie in improved engine performance through enhanced exhaust gas flow, a potentially more aggressive exhaust note, and a reduction in overall vehicle weight if constructed from lighter materials like stainless steel or titanium. Historically, enthusiasts have used these aftermarket components to increase horsepower and torque, particularly at higher engine speeds, while also personalizing the sound profile of their vehicle.