An exhaust system is usually a piping used to guide reaction exhaust gases away from a controlled combustion inside an engine. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Aftermarket exhaust systems are intended to replace OEM/stock exhaust systems in order to gain better performance for the vehicle. The horsepower of the vehicle will increase by the reduced back pressure of the OEM/stock exhaust system. Upon replacement of the high performance exhaust systems, you will be able to experience a more noticeable engine sound, which may not be desirable to everyone. Cosmetic enhancements is also possible by changing the visible parts of the exhaust system like the muffler tips.