Your exhaust system is more than a muffler. It is a series of pipes that run under your car, connected to your muffler and catalytic converter. The main function of your exhaust system is to control noise and to funnel exhaust fumes away from passengers.
In some ways, a car's exhaust system works like a chimney on your house, directing the byproducts from burning fuel away from the people inside. A car's exhaust system routes waste gases from the engine to the rear of the car, where they are discharged into the atmosphere. Exhaust gases contain dangerous substances such as carbon monoxide, which can be hazardous if allowed to flow into the passenger housing of the car.
The exhaust system also converts pollutants into less harmful byproducts, reduces the noise of the engine, and directs exhaust gases so they can be used to heat air and fuel before they go into the engine's cylinders to be burned. Finally, the exhaust system provides just the right amount of backpressure into the engine to improve its fuel-burning efficiency and increase performance.