Cummins B6.7, L9 DOC Filter 2018-2024: OEM 4395111

Reliable DOC Filtration for Cummins B6.7 & L9 Engines (2018–2024)

What is it?
The Diesel Oxidation Catalyst (DOC) filter for Cummins B6.7 and L9 engines (model years 2018–2024), with OEM reference 4395111, is a key emissions-control component. It converts hydrocarbons (HC) and carbon monoxide (CO) in the exhaust stream into cleaner, less harmful gases, helping the aftertreatment system maintain steady and dependable operation.

Why choose this DOC Filter?
Engineered to match original equipment specifications for both B6.7 and L9 platforms, this DOC filter offers precise fitment and reliable integration with your exhaust and aftertreatment system. A mismatched, worn, or blocked filter can cause increased exhaust restriction, more frequent regeneration cycles, or emissions-related fault codes. Installing the correct DOC filter helps maintain consistent exhaust flow and dependable system behavior.

Key Benefits
✅ Converts HC and CO into cleaner exhaust output
✅ Supports proper function of downstream aftertreatment components
✅ Helps maintain steady exhaust flow and reduce restriction
✅ Direct-fit design — no modifications required
✅ Built for heavy-duty, high-temperature operating environments

Applications
Ideal for medium- and heavy-duty trucks, commercial vehicles, and equipment powered by Cummins B6.7 or L9 engines from model years 2018 through 2024. This DOC filter is especially suited for fleet, vocational, and on-road applications where emissions compliance and reliable aftertreatment performance are essential.

Installation Notes
Before beginning service, ensure the exhaust and aftertreatment system has fully cooled. Remove the existing DOC filter and inspect nearby exhaust piping, sensors, and mounting hardware for soot buildup, cracks, or signs of wear. Install the replacement using new clamps, gaskets, and seals. After installation, clear any stored emissions-system fault codes and verify proper exhaust system behavior using diagnostic checks.

Final Thoughts
If your B6.7- or L9-equipped vehicle is experiencing elevated exhaust restriction, emissions warnings, or irregular aftertreatment system behavior, replacing the DOC filter with the correct OEM-specified unit is a practical way to restore clean, dependable exhaust flow. This component plays a vital role in maintaining the integrity of your emissions-control system and supporting dependable equipment operation.