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



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.

A manual gearbox contains oil that is designed to lubricate parts and transfer heat away from the

working components. There are no filters or cooling systems within a manual gearbox, so it is vital that

the oil is changed at recommended intervals to remove contamination and replace old, dirty oil that is

not working efficiently.


Gearbox failure prevention

Most gearbox faults start with a small problem that can easily be ignored. Worn shift levers, clutches

and incorrect oils are all responsible for a significant number of gearbox failures. Most of these are

preventable, and ignoring these issues can be a very costly mistake. A broken gearbox will severely

damage your car and your wallet. So if you think something might be wrong make sure you take your

vehicle to a garage at the first sign of trouble. For peace of mind and a lot of money saved, it makes