Cummins QSB4.5, 3.8 SCR Filter 2018-2024: OEM 5505816

Targeted SCR Filtration for Cummins QSB4.5 & 3.8 Engines (2018–2024)

What is it?
The Cummins QSB4.5, 3.8 SCR Filter (2018–2024), identified by OEM part number 5505816, is an emissions aftertreatment component engineered for Cummins QSB4.5 and 3.8-liter diesel engines built between 2018 and 2024. Installed ahead of the Selective Catalytic Reduction (SCR) catalyst, this filter conditions exhaust gases to support effective nitrogen oxide (NOx) conversion with Diesel Exhaust Fluid (DEF).

Why choose this SCR Filter?
This SCR filter is manufactured to meet Cummins’ original specifications for the QSB4.5 and 3.8 platforms, ensuring precise fitment and reliable interaction with DEF dosing hardware, emissions sensors, and control systems. Over time, exhaust deposits and soot buildup can reduce the filter’s ability to condition gases properly, which may lead to elevated backpressure, uneven NOx conversion, or emissions system alerts. Installing the correct OEM-specified filter helps maintain balanced exhaust conditioning and supports coordinated SCR operation.

Key Benefits
✅ Designed for Cummins QSB4.5 and 3.8 aftertreatment systems (2018–2024)
✅ Helps condition exhaust gases for more efficient NOx conversion
✅ Supports coordinated operation with DEF dosing and emissions sensors
✅ Direct replacement — no modifications required
✅ Built to withstand heavy-duty exhaust conditions

Applications
This SCR filter is suitable for medium- and heavy-duty vehicles equipped with Cummins QSB4.5 or 3.8 engines manufactured between 2018 and 2024. Typical applications include delivery trucks, vocational work vehicles, utility rigs, regional transport units, and other commercial platforms where regulated emissions behavior and compliance are important.

Installation Notes
Before servicing, make sure the exhaust and aftertreatment system has fully cooled. Remove the existing SCR filter and inspect nearby DEF lines, sensor connections, and mounting hardware for signs of soot buildup or wear. Install the replacement filter with proper seals and clamps to achieve a secure, leak-free fit. After installation, clear any stored system codes and verify correct aftertreatment performance using diagnostic tools.

Final Thoughts
If your Cummins QSB4.5 or 3.8-powered vehicle is experiencing emissions warnings, fluctuating NOx readings, or inconsistent aftertreatment behavior, replacing the SCR filter with the correct OEM-specified unit can help restore steadier exhaust conditioning and more predictable system performance. The Cummins QSB4.5, 3.8 SCR Filter (OEM 5505816) plays a key role in managing regulated emissions chemistry and supporting dependable engine operation across varied duty cycles.