Systems designed to expel combustion gases from an engine, reducing noise and harmful emissions. They typically consist of a manifold, catalytic converter, muffler, and tailpipe. The manifold collects gases from the engine cylinders, the catalytic converter reduces pollutants, the muffler dampens sound, and the tailpipe directs the gases away from the vehicle. Exhaust systems play a crucial role in engine performance, emissions control, and sound management, and can be modified to enhance power, efficiency, or create a desired sound.