Dependable Aftertreatment Filtration 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) of your engine’s aftertreatment system. Its role is to help oxidize harmful exhaust byproducts—such as hydrocarbons and carbon monoxide—into less harmful compounds before they proceed through the rest of the system, contributing to cleaner emissions and improved engine efficiency.
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 your vehicle’s original aftertreatment setup, reducing the likelihood of emissions faults and helping maintain dependable long-term performance. OEM-grade reliability means you can count on it in demanding conditions.
Key Benefits
✅ Designed for 2018–2021 Cummins B6.7 & L9 engines
✅ Helps lower hydrocarbons and carbon monoxide in exhaust
✅ Supports smoother and efficient aftertreatment operation
✅ Built to handle high-temperature exhaust environments
✅ Direct-fit replacement for simplified installation
Applications
This DOC filter is ideal for Cummins-powered commercial trucks, vocational vehicles, delivery fleets, and other diesel machinery built between 2018 and 2021 that rely on effective emissions control systems.
Installation Notes
Ensure the exhaust and aftertreatment system are fully cooled before beginning installation. Inspect surrounding sensors, gaskets, and connections for wear or contamination. Follow Cummins-recommended installation procedures and torque specifications for proper sealing. 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 offers a reliable, OE-grade replacement. Designed for accurate fit and trusted emissions control, it helps keep your engine compliant and running efficiently. Tamerx has this DOC filter in stock and ready to ship.