Trusted Emissions Filtration for Cummins B6.7 & L9 Engines (2018–2021)
What is it?
The Cummins B6.7, L9 DOC Filter OEM 4394859 is a vital emissions control component installed in the Diesel Oxidation Catalyst (DOC) of your engine’s aftertreatment system. It helps oxidize harmful exhaust pollutants like hydrocarbons and carbon monoxide into less harmful substances before they travel further through the emissions system, contributing to cleaner exhaust and improved engine efficiency.
Why choose OEM 4394859?
This DOC filter is engineered specifically for Cummins B6.7 and L9 engines manufactured from 2018 through 2021. Its precise OEM design ensures proper fitment and seamless integration with your vehicle’s original emissions hardware, reducing the likelihood of faults and helping maintain consistent, long-term performance. With genuine OEM construction, you’re investing in reliability and durability you can count on.
Key Benefits
✅ Built for 2018–2021 Cummins B6.7 & L9 engines
✅ Helps reduce hydrocarbons and carbon monoxide in exhaust
✅ Supports smoother operation of the aftertreatment system
✅ Constructed to withstand high-temperature exhaust environments
✅ Direct-fit replacement for easier installation
Applications
This DOC filter is ideal for Cummins-powered trucks and equipment built between 2018 and 2021. Typical applications include light- to heavy-duty commercial vehicles, vocational trucks, delivery fleets, and other diesel machinery requiring effective emissions control for daily performance.
Installation Notes
Ensure 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 system performance. After installation, verify that the emissions system is functioning correctly.
Final Thoughts
If your Cummins B6.7 or L9 engine is showing emissions-related alerts or reduced aftertreatment performance, the OEM 4394859 DOC filter provides 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.