One of the hardest worked parts of 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 vehicle's occupants
- Improving engine performance
- Improving fuel consumption
An exhaust system is composed of the following components
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 car's 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 before a replacement CAT being fitted.
Your car may have more than one silencer box fitted. The silencer is designed to absorb sound waves created by the engine and reduce 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.
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.