Cummins ISB 6.7L SCR Outlet Catalyst Module 2018-2022: OEM 4394691

Give Your Cummins ISB 6.7L the SCR Performance It Deserves

What is it?
The Cummins ISB 6.7L SCR Outlet Module, identified by OEM 4394691, is an emissions aftertreatment component designed for Cummins ISB 6.7L diesel engines produced between 2018 and 2022. Installed at the outlet of the Selective Catalytic Reduction (SCR) system, the module works with Diesel Exhaust Fluid (DEF) to convert harmful nitrogen oxide (NOx) emissions into nitrogen and water vapor before exhaust gases are released. It is an essential component for maintaining efficient aftertreatment operation and supporting emissions compliance.

Why choose this SCR Outlet Module?
Reliable SCR performance begins with a properly functioning outlet module. Manufactured to match Cummins ISB 6.7L specifications, this replacement module is compatible with factory-installed DEF dosing components, NOx sensors, and exhaust assemblies. Over time, catalyst contamination, DEF crystallization, repeated thermal cycling, and high exhaust temperatures can reduce SCR efficiency, potentially leading to emissions-related fault codes, decreased aftertreatment performance, or engine derate conditions. Installing the correct OEM replacement helps maintain dependable NOx conversion and consistent exhaust treatment.

Key Benefits
✅ Designed for Cummins ISB 6.7L engines (2018–2022)
✅ Supports efficient NOx reduction within the SCR system
✅ Helps maintain reliable aftertreatment performance
✅ Direct-fit replacement for accurate installation
✅ Built for durability in demanding commercial diesel applications

Applications
This SCR Outlet Module is commonly used on medium-duty trucks, buses, vocational vehicles, commercial fleet equipment, and industrial applications equipped with Cummins ISB 6.7L diesel engines from 2018 through 2022. These vehicles rely on dependable aftertreatment systems to meet emissions regulations while delivering reliable day-to-day performance.

Installation Notes
Before installation, allow the exhaust and aftertreatment system to cool completely. Inspect the DEF injector, NOx sensors, temperature sensors, exhaust piping, clamps, seals, and mounting hardware for contamination or wear. Install the replacement SCR outlet module using the appropriate gaskets and fasteners to ensure proper alignment and leak-free operation. After installation, verify SCR system functionality and clear any stored diagnostic fault codes using approved service equipment.

Final Thoughts
A dependable SCR Outlet Module helps your Cummins ISB 6.7L engine continue operating efficiently while supporting effective emissions control. The Cummins ISB 6.7L SCR Outlet Module (OEM 4394691) is designed to deliver reliable NOx reduction, consistent aftertreatment performance, and long-lasting durability for demanding diesel applications.