Diesel Oxidation Catalyst (DOC)
Similar to a catalytic converter, exhaust flows over the DOC structure, which is coated with a catalyst consisting of platinum and palladium.
Oxygen in the exhaust reacts with the catalyst to convert carbon monoxide (CO) to carbon dioxide (CO2), and to convert hydrocarbons (HC) to water (H2O).
DOC's are simple maintenance free devices which reduce greeenhouse gases.