Cummins QSB 4.5L SCR Outlet Catalyst Module 2014-2021: OEM 4353545

Reliable SCR Performance for Cummins QSB 4.5L Diesel Applications

What is it?
The Cummins QSB 4.5L SCR Outlet Catalyst Module, identified by OEM 4353545, is an aftertreatment component designed for Cummins QSB 4.5L diesel engines produced between 2014 and 2021. As part of the Selective Catalytic Reduction (SCR) system, this module helps process nitrogen oxide (NOx) emissions before exhaust gases leave the system. It works together with the Diesel Exhaust Fluid (DEF) system and other aftertreatment components to support proper emissions control.

Why choose this SCR Outlet Catalyst Module?
The SCR outlet catalyst operates in an environment exposed to continuous heat, exhaust gases, and changing operating conditions. Over time, deposits, contamination, or catalyst deterioration may affect its ability to process NOx efficiently. This can contribute to SCR-related diagnostic codes, emissions warnings, or aftertreatment system concerns. Using an OEM-matched replacement helps ensure the correct fit and compatibility for applicable Cummins QSB 4.5L systems.

Key Benefits
✅ Designed for Cummins QSB 4.5L engines (2014–2021)
✅ Helps support effective NOx conversion
✅ Works as part of the DEF and SCR aftertreatment system
✅ OEM-matched design for compatible applications
✅ Suitable for demanding diesel operating environments

Applications
This SCR Outlet Catalyst Module is intended for compatible Cummins QSB 4.5L-powered equipment manufactured between 2014 and 2021. These engines are used across a variety of commercial and industrial applications that depend on properly functioning aftertreatment systems. Always verify OEM 4353545 with the original component and specific engine configuration before installation.

Installation Notes
Allow the exhaust system to cool completely before removing the existing catalyst module. Check nearby exhaust connections, clamps, seals, sensors, DEF-related components, and mounting hardware for signs of damage, leakage, or buildup. Install the replacement module according to the appropriate service specifications, making sure all connections are correctly aligned and secured. Once installation is complete, check for diagnostic codes and confirm proper SCR system operation.

Final Thoughts
A dependable SCR outlet catalyst helps keep the aftertreatment system functioning correctly throughout everyday operation. The Cummins QSB 4.5L SCR Outlet Catalyst Module (OEM 4353545) offers a compatible replacement for 2014–2021 applications, supporting reliable NOx control and continued emissions system operation.