What does the exhaust system do? The automobile exhaust system mainly emits the exhaust gas discharged by the engine, and at the same time reduces the pollution of the exhaust gas and reduces the noise. Automobile exhaust system is mainly used for light vehicles, mini vehicles and passenger cars, motorcycles and other motor vehicles. The automobile exhaust system refers to a system that collects and emits exhaust gas, and is generally composed of an exhaust manifold, an exhaust pipe, a catalytic converter, an exhaust temperature sensor, an automobile muffler, and an exhaust tail pipe.