Cummins B6.7, L9 SCR 2018-2021: OEM 5418950

Streamlined Emissions Management for Cummins B6.7 & L9 Engines (2018–2021)

What is it?
The Cummins B6.7/L9 SCR assembly, identified by OEM 5418950, is an emissions aftertreatment component used on Cummins B6.7 and L9 diesel engines manufactured from 2018 through 2021. As part of the selective catalytic reduction system, it works in conjunction 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 rely on components that are precisely matched to the engine platform. This SCR unit is produced to Cummins’ original design standards, ensuring proper alignment with DEF dosing equipment, exhaust sensors, and electronic controls on both the B6.7 and L9 platforms. When SCR components lose efficiency, emissions alerts or inconsistent exhaust treatment can occur. Using the correct OEM-specified assembly helps maintain steady system behavior and predictable emissions control.

Key Benefits
✅ Platform-specific design for Cummins B6.7 and L9 engines
✅ Supports consistent NOx processing through DEF chemistry
✅ Helps maintain stable coordination across aftertreatment components
✅ Direct replacement with no fabrication or adjustments required
✅ Designed for continuous operation in high-temperature exhaust conditions

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. Common applications include delivery fleets, vocational equipment, regional transport vehicles, and other work platforms where emissions consistency is critical to daily operation.

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 signs of wear or buildup. Install the replacement assembly using appropriate seals and fasteners to ensure correct positioning. After installation, clear stored fault codes and confirm proper aftertreatment operation with diagnostic tools.

Final Thoughts
If your Cummins B6.7- or L9-powered vehicle is experiencing emissions warnings, fluctuating NOx readings, or irregular 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 5418950) plays an important role in maintaining emissions system stability and dependable vehicle operation.