With Expertise Built In™, the OTR Diesel Oxidation Catalyst helps balance the exhaust emissions of on-highway diesel trucks. Maintenance-free and engineered to last as long as the engine, this diesel oxidation catalyst removes unburned hydrocarbons, soluble organic fraction, carbon monoxide, and unregulated contaminants from emissions. The diesel oxidation catalyst is essential to the thermal management of the diesel particulate filter, maintaining your up time. FleetPride is your First Click in Heavy Duty®.