Catalytic Converter

The oxidizing catalytic converter is fitted in the front section of the exhaust system, after the Heated Oxygen Sensor (HO2S). The catalytic converter assembly is common to vehicles with or without the DPF, however, the catalyst coating specification varies depending on the market.

The HO2S monitors the exhaust gasses leaving the engine. The engine management system uses this information to provide accurately metered quantities of fuel to the combustion chambers to ensure the most efficient use of fuel and to minimize the exhaust emissions.

For additional information, refer to: Electronic Engine Controls .

The catalytic converter further reduces the carbon monoxide and hydrocarbons content of the exhaust gases. In the catalytic converter the exhaust gases are passed through honeycombed ceramic elements coated with a special surface treatment called a 'washcoat'.

The washcoat increases the surface area of the ceramic elements by a factor of approximately 7000. On top of the washcoat is a coating containing platinum, which is the active constituent for converting harmful emissions into inert by-products. The platinum adds oxygen to the carbon monoxide and the hydrocarbons in the exhaust gases, to convert them into carbon dioxide and water respectively.