Catalytic Converter: Description and Operation

PURPOSE
The Reduction Oxidation (REDOX) catalyst is an oxidation catalyst specifically formulated to withstand the rigorous requirements of medium weight heavy duty trucks (8500 to 14,000 lbs). It simultaneously controls HC, CO and NOx depending on the exhaust gas mixture stoichiometry.

OPERATION
In order to maintain the converter's feed gas (exhaust) oxygen content at a high level to obtain the maximum oxidation for producing the heated chemical reaction, the oxidation catalyst requires the use of a secondary air source. This source is provided by the secondary air injection system.

CONSTRUCTION
The catalytic converter assembly consists of a structured shell containing a monolithic substrate-a ceramic, honeycomb construction. The catalytic converter system is protected by several devices that block out the secondary air supply from the secondary air injection system when the engine is laboring under any abnormal hot or cold operating situation.