Catback

Catback, short for cat-back exhaust, is a class of automotive exhaust systems that replaces the piping and components from just after the catalytic converter to the exhaust tip. It does not include the catalytic converter itself or upstream pre-catalytic sections, such as the downpipe. Catback systems are offered as direct-fit kits or universal assemblies and are popular as aftermarket upgrades aimed at improving exhaust flow and sound.

Common components include a larger-diameter main pipe, a muffler or resonator, a mid-pipe portion, and a final exhaust tip. Materials are typically stainless steel or aluminized steel, with stainless steel versions offering higher corrosion resistance. Installations can be bolt-on with mounting hardware; some vehicles require more extensive modifications or welding, and many users seek professional installation.

Performance and sound characteristics vary by vehicle and configuration but generally include reduced backpressure and a deeper or more aggressive exhaust note. Horsepower and torque gains are usually modest and depend on the vehicle’s stock exhaust design, engine tuning, and other modifications. Some catbacks also reduce weight. They do not typically improve fuel economy and may increase compliance challenges in regions with strict emissions rules.

Legality and compliance depend on local regulations; some jurisdictions restrict aftermarket exhaust noise or require emissions-legal parts. Maintenance involves inspecting hangers and gaskets for leaks and corrosion, periodically cleaning or replacing worn components, and ensuring heat shields and supports remain secure. Catback is one of several aftermarket exhaust categories, alongside axle-back and full-system upgrades.