Catalytic Converter: Description and Operation

Catalyst Configuration:

PURPOSE
The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of pollutants from the exhaust gas stream.

OPERATION
A single bed monolith catalytic converter is used in combination with two different types of catalyst. These are an oxidation catalyst and a three-way (reduction/oxidation) catalyst. The catalysts have coatings that contain platinum and palladium.

The oxidation catalyst lowers the level of Hydrocarbons (HC) and carbon monoxide (CO). The three-way catalyst lowers the levels of oxides of nitrogen (NO3) as well as HC and CO.

NOTES:
^ This device sometimes requires the use of heat shields, due to its high operating temperatures. The heat shields are necessary to protect chassis components, passenger compartment, and other areas from heat related damage.
^ A small diameter fuel tank filler neck is used on catalytic converter equipped vehicles to prevent the use of leaded fuel pump nozzles.