Cummins B6.7, L9 SCR 2018-2021: OEM 5418533

Coordinated Emissions Control for Cummins B6.7 & L9 Engines (2018–2021)

What is it?
The Cummins B6.7/L9 SCR assembly, identified by OEM 5418533, is an emissions aftertreatment component designed for Cummins B6.7 and L9 diesel engines produced between 2018 and 2021. Operating as part of the SCR process, it works with Diesel Exhaust Fluid (DEF) to help convert nitrogen oxides (NOx) in the exhaust into nitrogen and water before release.

Why choose this SCR Assembly?
Aftertreatment systems depend on precise compatibility between components. This SCR unit is built to Cummins’ original specifications for both the B6.7 and L9 platforms, ensuring correct fitment and reliable interaction with DEF dosing systems, sensors, and control modules. When SCR efficiency declines, emissions alerts and irregular exhaust behavior can occur. Using the correct OEM-matched assembly helps maintain consistent system operation.

Key Benefits
✅ Designed for Cummins B6.7 and L9 aftertreatment systems (2018–2021)
✅ Supports dependable NOx conversion through SCR chemistry
✅ Helps maintain stable coordination with emissions sensors and controls
✅ Direct-fit replacement — no modifications required
✅ Built to handle sustained high-temperature exhaust environments

Applications
This SCR assembly is used in medium- and heavy-duty commercial vehicles equipped with Cummins B6.7 or L9 engines from the 2018–2021 model years. Typical applications include delivery trucks, vocational equipment, regional transport vehicles, and fleet operations where emissions system consistency is essential.

Installation Notes
Allow the exhaust and aftertreatment system to cool completely before service. Remove the existing SCR unit and inspect surrounding DEF lines, sensors, and mounting hardware for wear or buildup. Install the replacement assembly using proper seals and fasteners to ensure a secure, leak-free fit. After installation, clear any stored fault codes and verify correct system operation using diagnostic checks.

Final Thoughts
If your Cummins B6.7- or L9-powered vehicle is showing emissions warnings or inconsistent aftertreatment behavior, replacing the SCR assembly with the correct OEM-specified component can help restore balanced exhaust treatment. The Cummins B6.7/L9 SCR (OEM 5418533) plays a vital role in maintaining emissions system stability and dependable vehicle operation.