Proven 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 the Diesel Oxidation Catalyst (DOC) in your engine’s aftertreatment system. It’s responsible for oxidizing harmful exhaust pollutants—such as hydrocarbons and carbon monoxide—into less harmful substances before they move through the rest of the emissions system, helping your engine stay cleaner and compliant.
Why choose OEM 4394859?
This DOC filter is engineered specifically for Cummins B6.7 and L9 engines produced from 2018 through 2021. With its precise OEM fit and quality construction, it integrates seamlessly with your vehicle’s original aftertreatment components. This helps reduce emissions-related faults, maintain dependable performance, and support long-term durability under everyday operating conditions.
Key Benefits
✅ Designed for 2018–2021 Cummins B6.7 & L9 engines
✅ Helps lower hydrocarbons and carbon monoxide in exhaust
✅ Supports smoother emissions system operation
✅ Built 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-powered machinery built between 2018 and 2021 that rely on effective emissions control for daily performance.
Installation Notes
Before installation, make sure the exhaust and aftertreatment system are completely cool. 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 performance. After installation, verify that the emissions system is operating correctly.
Final Thoughts
If your Cummins B6.7 or L9 engine is experiencing emissions-related alerts or reduced aftertreatment efficiency, the OEM 4394859 DOC filter offers a dependable, OE-grade replacement option. Designed for precise 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.