Cummins B6.7 SCR 2018-2021: OEM 5418550

Balanced NOx Conversion for Cummins B6.7 Engines (2018–2021)

What is it?
The Cummins B6.7 SCR (Selective Catalytic Reduction) assembly, carrying OEM part number 5418550, is a key emissions aftertreatment component for Cummins B6.7 diesel engines produced between 2018 and 2021. Operating with Diesel Exhaust Fluid (DEF), this module supports a chemical process that turns nitrogen oxides (NOx) in the exhaust into nitrogen and water before the gases exit the system, helping the engine meet emissions requirements.

Why choose this SCR Assembly?
This SCR unit is engineered to Cummins’ original specifications for the B6.7 platform, ensuring accurate fitment and dependable interaction with DEF delivery systems, sensors, and engine control modules. As components age, SCR performance can decline, which may reduce NOx conversion efficiency and trigger emissions alerts. Installing the correct OEM-specified SCR helps maintain consistent emissions behavior and coordinated aftertreatment system responses.

Key Benefits
✅ Specifically designed for Cummins B6.7 aftertreatment systems (2018–2021)
✅ Helps enable reliable NOx conversion with DEF interaction
✅ Supports coordinated operation with related emissions components
✅ Direct-fit replacement — no adjustments required
✅ Built for heavy-duty exhaust environments

Applications
This SCR assembly is suitable for medium- and heavy-duty trucks and commercial vehicles powered by Cummins B6.7 engines manufactured between 2018 and 2021. It’s commonly found in delivery fleets, vocational trucks, regional haul rigs, and other equipment where dependable emissions management and regulatory compliance are integral to daily operation.

Installation Notes
Before servicing, let the exhaust and aftertreatment system cool completely. Remove the existing SCR module and inspect nearby DEF lines, sensors, and mounting hardware for signs of wear, soot buildup, or damage. Install the replacement assembly using proper seals and fasteners to ensure a secure and leak-free fit. After installation, clear any stored fault codes and verify correct emissions system behavior using appropriate diagnostic checks.

Final Thoughts
If your Cummins B6.7-equipped vehicle is showing NOx-related alerts, uneven emissions readings, or inconsistent aftertreatment behavior, replacing the SCR assembly with the correct OEM-specified part can help restore coordinated emissions control. The Cummins B6.7 SCR (OEM 5418550) plays a central role in managing exhaust chemistry and supporting reliable vehicle operation across a variety of duty cycles.