An exhaust system is usually tubing used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall system design, the exhaust gas may flow through one or more of:
Cylinder head and exhaust manifold
A turbocharger to increase engine power.
A catalytic converter to reduce air pollution.
A muffler (North America) / silencer (Europe), to reduce noise.

An exhaust pipe must be carefully designed to carry toxic and/or noxious gases away from the users of the machine. Indoor generators and furnaces can quickly fill an enclosed space with carbon monoxide or other poisonous exhaust gases if they are not properly vented to the outdoors. Also, the gases from most types of machine are very hot; the pipe must be heat-resistant, and it must not pass through or near anything which can burn or can be damaged by heat. A chimney serves as an exhaust pipe in a stationary structure. For the internal combustion engine it is important to have the Exhaust System "Tuned" (refer to tuned pipe) for optimal efficiency.

Upgrading your car, or Van's auto exhaust system is a great way to build horsepower, free up trapped torque, and improve upon anemic-sounding factory systems. The larger pipes, low-restriction mufflers, and tuned resonators of a well-designed performance exhaust system can make a world of difference on your vehicle. We have truck and auto exhaust systems from Flowmaster exhaust, Gibson exhaust, and a host of other highly-respected exhaust system manufacturers, with applications ranging from Honda Civic exhaust systems to LS1 Camaro exhaust systems. Those of you with newer vehicles are no doubt thinking, "what about emission control regulations?" The government doesn't take kindly to bypassing smog equipment, something the smart tuner keeps in the back of his or her mind whenever an upgrade is planned. Enter the cat-back exhaust system: For newer vehicles, Flowmaster exhaust, Gibson exhaust, and many of our other premium manufacturers make cat-back exhaust systems (short for catalyst-back exhaust systems) to fit your needs. These cat-back exhaust systems leave the emissions-control gear in place, but allow you to put large-diameter exhaust pipes and low-restriction performance mufflers into the system after the catalytic converter. The net result is lower auto exhaust backpressure, more horsepower, more torque, and a much hotter sound, all while staying perfectly legal.

The exhaust system is one of the most hard working components on your vehicle. It is constantly in use whilst the engine is running. An exhaust system on most vehicles usually comprises of four sections:

• Manifold
• Front Downpipe
• Centre Section
• Rear silencer box

Also on all vehicles registered after 1993 a catalytic converter is fitted. The most common section to become defective is the rear silencer as moisture gathers inside the box and attacks the metal. Corrosion from the inside results in hole, which causes the exhaust to blow. A defective exhaust will mean the vehicle fails the MOT test. It also causes excessive noise; thereby rendering the vehicle illegal which could lead to a fixed penalty fine. An unchecked exhaust may also result in fumes entering the car, which can lead to headaches, sickness and drowsiness.

Catalytic Converters
Catalytic converters are now fitted to all cars to remove harmful pollution from the exhaust gases. This expensive and high-tech component fits in the exhaust system and looks on the outside like a typical silencer box.

The catalytic converter is an integral part of the engine performance system and sensors control the gases entering and leaving the catalytic converter are controlled by the engine management system.

The catalytic converter effectiveness is measured by testing the exhaust gas emissions. This is an important part of the MOT and service requirements on all cars today.