Cummins B6.7, L9 DOC Filter 2018-2021: OEM 4394859

Trusted Emissions Filter for Cummins B6.7 & L9 Engines (2018–2021)

What is it?
The Cummins B6.7, L9 DOC Filter OEM 4394859 is an important emissions control component installed in the Diesel Oxidation Catalyst (DOC) of your engine’s aftertreatment system. It helps oxidize harmful exhaust pollutants—such as hydrocarbons and carbon monoxide—into less harmful compounds before the exhaust continues through the rest of the system, promoting cleaner emissions and efficient engine performance.

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 reliable integration with your vehicle’s original aftertreatment components, helping reduce the chance of emissions faults while providing consistent, long-term performance. With genuine OEM construction, you get dependable durability and trusted operation.

Key Benefits
✅ Built for 2018–2021 Cummins B6.7 & L9 engines
✅ Helps decrease hydrocarbons and carbon monoxide in exhaust
✅ Supports smoother aftertreatment system function
✅ Designed to withstand high-temperature exhaust conditions
✅ Direct-fit replacement for simpler installation

Applications
This DOC filter is ideal for Cummins-powered commercial trucks, vocational vehicles, delivery fleets, and other diesel machinery produced between 2018 and 2021 that depend on compliant emissions control systems.

Installation Notes
Before installation, make sure the exhaust and aftertreatment system are completely cool. Inspect nearby sensors, gaskets, and connections for 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 functioning correctly.

Final Thoughts
If your Cummins B6.7 or L9 engine is showing emissions-related alerts or reduced aftertreatment capability, the OEM 4394859 DOC filter delivers a dependable, OE-grade replacement option. 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.