Cummins QSB 6.7L SCR Filter 2011-2018: OEM 4387680

Balanced NOx Conditioning for Cummins QSB 6.7L Engines (2011–2018)

What is it?
The Cummins QSB 6.7L SCR Filter (2011–2018), designated by OEM part number 4387680, is an aftertreatment component engineered for Cummins QSB 6.7-liter diesel engines produced between 2011 and 2018. This filter is part of the Selective Catalytic Reduction (SCR) system and helps prepare exhaust gases so that nitrogen oxides (NOx) can be more effectively reduced when DEF (Diesel Exhaust Fluid) is injected downstream in the SCR catalyst.

Why choose this SCR Filter?
This SCR filter is manufactured to Cummins’ original specifications for the QSB 6.7L platform, ensuring proper fitment and dependable interaction with DEF dosing components, emissions sensors, and the engine control system. Over time, soot, ash, and other exhaust deposits can build up in the filter, reducing its ability to condition the exhaust stream properly. Replacing the filter with the correct OEM-specified unit helps maintain consistent exhaust conditioning and supports coordinated SCR performance.

Key Benefits
✅ Designed specifically for Cummins QSB 6.7L aftertreatment systems (2011–2018)
✅ Helps condition exhaust gases for improved NOx reduction
✅ Supports stable coordination with DEF dosing hardware and emissions sensors
✅ Direct replacement — no modifications required
✅ Built for heavy-duty exhaust environments

Applications
This SCR filter is suitable for medium- and heavy-duty vehicles equipped with Cummins QSB 6.7L engines manufactured between 2011 and 2018. It’s commonly found in commercial trucks, vocational work rigs, delivery vehicles, and other platforms where emissions compliance and regulated exhaust behavior are key to daily operation.

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

Final Thoughts
If your Cummins QSB 6.7L-equipped vehicle is experiencing NOx-related alerts, uneven emissions readings, or irregular aftertreatment behavior, replacing the SCR filter with the correct OEM-specified part can help restore steadier exhaust conditioning and more predictable system responses. The Cummins QSB 6.7L SCR Filter (OEM 4387680) plays a key role in maintaining regulated exhaust chemistry and supporting dependable engine operation across varied duty cycles.