Which statement about the Diesel Oxidation Catalyst (DOC) within the ATD is true?

Which statement about the Diesel Oxidation Catalyst (DOC) within the ATD is true?

• A. It oxidizes hydrocarbons and carbon monoxide.
• B. It stores diesel fuel.
• C. It filters soot.
• D. It cools the exhaust stream.

Answer: (A)

The function of the Diesel Oxidation Catalyst is to promote the oxidation of pollutants in the diesel exhaust. As exhaust passes through the DOC, hydrocarbons and carbon monoxide react with oxygen on the catalyst surface, forming carbon dioxide and water vapor. This reduces HC and CO emissions from the engine. It does not store fuel, filter soot, or cool the exhaust, which are roles for other components. So the statement that it oxidizes hydrocarbons and carbon monoxide is the accurate description.

The function of the Diesel Oxidation Catalyst is to promote the oxidation of pollutants in the diesel exhaust. As exhaust passes through the DOC, hydrocarbons and carbon monoxide react with oxygen on the catalyst surface, forming carbon dioxide and water vapor. This reduces HC and CO emissions from the engine. It does not store fuel, filter soot, or cool the exhaust, which are roles for other components. So the statement that it oxidizes hydrocarbons and carbon monoxide is the accurate description.