Made with Expertise Built In™, the OTR Diesel Oxidation Catalyst (DOC) for ISX oxidizes and eliminates unburned hydrocarbons, soluble organic fraction, carbon monoxide, and unregulated contaminants from on-highway diesel trucks’ emissions. This heavy duty diesel oxidation catalyst is also a vital part of the DPF’s thermal management. FleetPride is your First Click in Heavy Duty®.