Cummins B6.7, L9 DOC Filter 2018-2021: OEM 4394859

Enhanced Emissions Filtration for Cummins B6.7 & L9 (2018–2021)

What is it?
The Cummins B6.7, L9 DOC Filter OEM 4394859 is a crucial part of your engine’s aftertreatment system, located in the Diesel Oxidation Catalyst (DOC). It helps oxidize harmful exhaust pollutants—such as hydrocarbons and carbon monoxide—into less harmful gases before they travel through the rest of the emissions system, promoting cleaner exhaust and stronger overall engine performance.

Why choose OEM 4394859?
This DOC filter is engineered specifically for Cummins B6.7 and L9 engines produced from 2018 through 2021. Its precise OEM design ensures accurate fit and seamless integration with your existing aftertreatment components, helping reduce emissions faults and maintain reliable performance over time. With genuine OEM construction, you’re choosing durability and dependable emissions control.

Key Benefits
✅ Engineered for 2018–2021 Cummins B6.7 & L9 engines
✅ Helps lower hydrocarbons and carbon monoxide in exhaust
✅ Promotes smoother emissions system operation
✅ Built to withstand high-temperature exhaust environments
✅ Direct-fit replacement for easier installation

Applications
This DOC filter suits Cummins-powered commercial trucks, vocational vehicles, delivery fleets, and other diesel-powered equipment built from 2018 to 2021 that require effective emissions control for compliant, efficient operation.

Installation Notes
Make sure the exhaust and aftertreatment system are fully cooled before beginning installation. Inspect nearby sensors, gaskets, and connections for wear or contamination. Follow Cummins-recommended installation procedures and torque specifications to ensure proper sealing and function. After installation, verify the emissions system is operating correctly.

Final Thoughts
If your Cummins B6.7 or L9 engine is showing emissions-related warnings or diminished aftertreatment effectiveness, the OEM 4394859 DOC filter offers a reliable, OE-grade replacement solution. Designed for accurate fit and consistent emissions control, it helps keep your engine compliant and running smoothly. Tamerx has this DOC filter in stock and ready to ship.