In many 2007 and later model year heavy duty trucks, the BIG Machine Parts Diesel Oxidation Catalyst (DOC) plays a vital role in the thermal management of your DPF. A small amount of fuel is injected in front of the DOC which then combusts and allows the release of heat for the regeneration of soot in the system DPF.

With over 125 designs and counting, BigMachineParts.com and BIG Machine Parts have the largest selection of aftermarket DPFs and DOCs in the market today! Manufactured of 409 steel in North America, this BIG Machine Parts DOC is a new, direct fit replacement for the OEM system and is designed to operate at the same capacity as the original part at a value price. New manufactured means there is no core charge or core return hassle. .

• Mechanically and chemically engineered to work with OEM sensors and Engine Operating Parameters
• New, never reman or reconditioned
• Coated with PGM coatings...matching OEM
• NO CORE CHARGE
• Warranty Information

Application Summary: Cummins ISB, ISC Engines