Catalytic Converters

A catalytic converter is part of the exhaust system. It is designed to convert toxic gases into more environmentally friendly by-products. Conversion of exhaust gases begins after reaching an operating temperature of approx. 200 degrees Celsius.
The optimum operating range is usually between 400 and 600 degrees Celsius. The core of a catalytic converter is a ceramic matrix coated with precious metals. They were fitted to all cars after 1986.

The symptoms of a faulty catalytic converter include: Blockage in the exhaust system leading to poor engine performance caused by the core melting (due to persistent engine misfire or unburned fuel reaching the catalytic converter) Rattling sound caused by the core disintegrating No obvious symptoms but failing an exhaust emissions test.

All these symptoms cause poisonous, polluting fumes which can be detected by an exhaust gas analysis.
Degradation of the core occurs over time but is accelerated by engine faults.  Even with regular servicing and no engine faults, converters often need replacing after 80,000 km or after 5 years use. It is important that they are checked regularly in order to maintain proper function: aiding in the maintenance of an economical and efficient vehicle (good for the long term health of your car and your bank account) and reducing toxic gases (good for the environment).