What you need to know

Although there are no moving parts in an exhaust system, it's function and placement on the vehicle means it is one of the hardest worked components on the car. Effects of rust and corrosion by toxic wastes combine to attack the metals of the system leading to noisy and dangerous failures. A 'blown', noisy exhaust is illegal and can lead to a fine. In addition, the leakage of toxic fumes from a failed exhaust into the car can lead to headaches, sickness and drowsiness, with the possibility of catastrophic results. Here are the key components of a typical exhaust system:

Tail Pipe

The tail pipe allows free exit of the exhaust gases into the atmosphere.

Silencer Box

There may be more than one silencer box fitted to your car. The silencer is specially designed to absorb sound waves created by the engine and reduce this noise to a legally and environmentally acceptable level.

Exhaust Manifold Connection

The front piece of the exhaust pipe has a special coupling designed to be attached directly to the exhaust manifold which in turn is part of the engine. To absorb the varying stresses of the engine's vibration, the front piece of the exhaust pipe may contain a flexible section to avoid damage to both the exhaust system and the engine.

Catalytic Converter

Modern exhaust systems are designed to remove most of the harmful pollutants from the exhaust gases before release into the atmosphere. This is done by a component fitted into the exhaust system called a Catalytic Converter, or CAT.

A specially lined box filters and converts the hot polluted exhaust gases into a much more environmentally friendly mixture. This mixture then passes along the exhaust pipe to the silencer or silencers before being expelled through the tail pipe and into the atmosphere.