Cummins QSL 8.9L SCR Filter 2011-2018: OEM 4328947

Targeted NOx Conditioning for Cummins QSL 8.9L Engines (2011–2018)

What is it?
The Cummins QSL 8.9L SCR Filter (2011–2018), identified by OEM part number 4328947, is a vital emissions aftertreatment component engineered for Cummins QSL 8.9-liter diesel engines manufactured between 2011 and 2018. Positioned upstream of the Selective Catalytic Reduction (SCR) catalyst, this filter helps condition the exhaust stream so nitrogen oxides (NOx) can be more effectively reduced when Diesel Exhaust Fluid (DEF) is applied downstream.

Why choose this SCR Filter?
This SCR filter is manufactured to Cummins’ original specifications for the QSL 8.9L platform, ensuring accurate fitment and dependable integration with DEF delivery systems, emissions sensors, and aftertreatment controls. Over time, soot, ash, and other combustion by-products can accumulate in the filter and reduce its effectiveness, potentially increasing backpressure or leading to inconsistent NOx conditioning. Installing the correct OEM-specified filter helps maintain balanced exhaust conditioning and supports coordinated SCR operation.

Key Benefits
✅ Designed specifically for Cummins QSL 8.9L aftertreatment systems (2011–2018)
✅ Helps prepare exhaust gases for efficient NOx conversion
✅ Supports stable interaction with DEF dosing hardware and emissions sensors
✅ Direct-fit replacement — no modifications required
✅ Built for heavy-duty exhaust conditions and extended service life

Applications
This SCR filter is ideal for medium- and heavy-duty vehicles equipped with Cummins QSL 8.9L engines manufactured from 2011 through 2018. It’s commonly used in long-haul trucks, regional transport rigs, vocational work vehicles, construction equipment, and other commercial platforms where reliable emissions conditioning and compliance are essential.

Installation Notes
Before servicing, allow the exhaust and aftertreatment system to fully cool to avoid burns or damage. Remove the existing SCR filter and inspect nearby DEF lines, sensor connections, and mounting hardware for soot buildup, damage, or wear. Install the replacement filter using the proper seals and clamps to ensure a secure, leak-free fit. After installation, clear any stored system codes and verify proper SCR system behavior with diagnostic tools.

Final Thoughts
If your Cummins QSL 8.9L-equipped vehicle is showing NOx-related warnings, uneven emissions 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 QSL 8.9L SCR Filter (OEM 4328947) plays a key role in managing regulated exhaust chemistry and supporting dependable engine operation across varied duty cycles.