Dependable Aftertreatment Filtration for Cummins B6.7 & L9 (2018–2021)
What is it?
The Cummins B6.7, L9 DOC Filter OEM 4394859 is an essential emissions control piece located in the Diesel Oxidation Catalyst (DOC) section of your engine’s aftertreatment system. It works by oxidizing harmful exhaust pollutants—like hydrocarbons and carbon monoxide—into less harmful compounds before they progress through the rest of the system, promoting cleaner exhaust and efficient engine operation.
Why choose OEM 4394859?
This DOC filter is specifically designed for Cummins B6.7 and L9 engines manufactured from 2018 through 2021. Its precise OEM engineering ensures the correct fit and reliable integration with your factory aftertreatment components, helping minimize emissions-related faults and support long-term performance. With genuine OEM construction, you get durability and day-to-day dependability.
Key Benefits
✅ Built for 2018–2021 Cummins B6.7 & L9 engines
✅ Helps reduce hydrocarbons and carbon monoxide in exhaust
✅ Supports smoother emissions system operation
✅ Designed to tolerate high-temperature exhaust environments
✅ Direct-fit replacement for easier installation
Applications
This DOC filter is ideal for Cummins-powered commercial trucks, vocational vehicles, delivery fleets, and other diesel equipment built between 2018 and 2021 that rely on compliant and efficient emissions control systems.
Installation Notes
Before installation, ensure the exhaust and aftertreatment system are completely cooled. Inspect nearby sensors, gaskets, and connections for wear or contamination. Follow Cummins-recommended installation procedures and torque specifications to ensure proper sealing and system performance. After installation, verify the emissions system is operating correctly.
Final Thoughts
If your Cummins B6.7 or L9 engine is showing emissions-related alerts 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 efficiently. Tamerx has this DOC filter in stock and ready to ship.