The catalytic converter consists of a stainless steel shell housing a ceramic substrate (monolith). This substrate has numerous fine channels running lengthways through it, which increase the effective surface area of the catalyst.

A highly porous coating (wash coat), containing precious metals such as platinum, palladium and rhodium, is applied to the surface of the substrate material.

These precious metals are the actual catalysts on which the chemical reactions take place.

Emissions of the pollutants CO and HC are reduced by up to 70%.

The catalytic converter for diesel engines oxidises carbon monoxide to carbon dioxide and hydrocarbons to carbon dioxide and water vapour.

Diesel engines work with a high volume of excess air, which means that their exhaust gas always contains a high proportion of oxygen.