One of the hardest worked parts on your car is the exhaust system. It is a series of pipes linking the engine to a silencer and a catalytic converter, it performs several functions including;

Controlling noise
Directing exhaust fumes away from the vehicles occupants
Improving engine performance
Improving fuel consumption

An exhaust system is composed of the following components:

Exhaust Manifold

The exhaust manifold acts as a funnel, collecting the exhaust gases from all cylinders of the engine then releasing them through a single opening, often referred to as the front pipe. Catalytic Converters (CAT’s) are an integral part of a car’s engine management system, not simply a part of the exhaust system.

They are designed to reduce:

Carbon Monoxide
Hydrocarbons or Volatile Organic Compounds
Nitrogen Oxides

The CAT Can Fail because of Carbon pollution where un-burnt fuel, oil or antifreeze enters the exhaust system, leading to a partial or complete blockage. This could hamper your cars performance and make the exhaust system noisy.

Converter Meltdown is another form of failure common causes are:

Lack of servicing
Some catalysts contain ceramic bricks which can break if they suffer a knock
Engine misfires or bump starting a vehicle
Leaded fuel can poison the catalyst
Leakage of welds or pipes

Catalysts are exposed to extremes of heat and mechanical stress which can result in damage after a long period of service.

The illumination of the Malfunction Indicator Light (MIL) does not necessarily mean the CAT is faulty. Diagnosis is required prior to a replacement CAT being fitted.

Silencer Box

Your car may have more than one silencer box fitted. The silencer is designed to absorb sound waves created by the engine and reduces this to a level that is legally and environmentally acceptable. The silencer joins onto the tailpipe at one end and the catalytic converter at the other.

Tail Pipe

The tail pipe is the part of the exhaust that extends from the back of the car. It allows the exhaust gases to exit into the atmosphere.