Reliable Aftertreatment Filtration Solution for Cummins B6.7 & L9 (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) portion of your engine’s aftertreatment system. Its purpose is to oxidize harmful exhaust pollutants—like hydrocarbons and carbon monoxide—into less harmful compounds before they continue through the rest of the emissions system, helping your engine run cleaner and more efficiently.
Why choose OEM 4394859?
This DOC filter is engineered specifically for Cummins B6.7 and L9 engines manufactured between 2018 and 2021. With its precise OEM fit and quality construction, it integrates seamlessly with the vehicle’s original aftertreatment components. This helps lessen the chance of emissions faults, supports reliable operation, and reinforces long-term durability.
Key Benefits
✅ Designed for 2018–2021 Cummins B6.7 & L9 engines
✅ Reduces hydrocarbons and carbon monoxide in exhaust
✅ Promotes efficient operation of the aftertreatment system
✅ Built to handle high-temperature exhaust environments
✅ Direct-fit replacement for streamlined installation
Applications
This DOC filter is ideal for Cummins-powered commercial trucks, vocational vehicles, fleet rigs, and other diesel machinery built from 2018 through 2021 that require consistent emissions control for daily performance.
Installation Notes
Before installation, ensure the exhaust and aftertreatment system are completely cooled. Inspect nearby sensors, gaskets, and connections for signs of wear or contamination. Follow Cummins-recommended installation procedures and torque specifications to ensure proper sealing and function. After installation, verify that the emissions system is operating as expected.
Final Thoughts
If your Cummins B6.7 or L9 engine is showing emissions-related alerts or reduced aftertreatment effectiveness, the OEM 4394859 DOC filter delivers a reliable OE-grade replacement solution. Designed for precise fit and consistent emission control, it helps keep your engine compliant and operating efficiently. Tamerx has this DOC filter in stock and ready to ship.