• Engine Platforms: Cummins ISB 6.7 (on-highway) and QSB 6.7 (off-highway/industrial).

• Emissions Standards: Primarily designed for EPA10, EPA13, and Tier 4 Final regulations.

• Primary Vehicle Applications:

  • Medium-Duty Trucks: Freightliner M2 106, International MV Series, Ford F-650/F-750.

  • Buses: Blue Bird Vision, Thomas Built Saf-T-Liner C2.

  • Vocational: Emergency vehicles (Ambulances/Fire trucks), Yard Spotters, and medium-duty dump trucks.

Key Characteristics:

• The Soot Trap: Unlike a standard muffler or a catalyst, the DPF has blocked channels (honeycomb structure) that force exhaust gases through porous walls, physically trapping the black carbon soot inside.

• Cleaning Cycles (Regeneration): As the filter fills up, the engine performs a "Regen." It injects fuel into the exhaust to raise the temperature and burn the stored soot into a tiny amount of ash.

• Serviceable Component: While soot can be burned off, the remaining ash cannot. This means the DPF must be removed and professionally cleaned or replaced every 250,000 to 400,000 miles, depending on duty cycle and oil consumption.

• Standardized Design: Because PACCAR (Kenworth/Peterbilt) often utilizes both Cummins and MX engines, the DPF units for these platforms are often standardized in size, allowing the same filter core to fit multiple engine brands across the same chassis.

• Frequent or "Stubborn" Regenerations: If your truck requests a parked regen shortly after finishing one, or the soot level stays high despite a successful cycle, the filter is likely "ash-loaded." Ash takes up permanent space, leaving no room for new soot.

• Soot in the Tailpipe: A healthy DPF should have a perfectly clean outlet. If you see black residue inside the exhaust tip, the ceramic substrate inside the DPF is likely cracked or "melted," allowing raw soot to pass through.

• Engine Derate: The ECM monitors the pressure difference across the filter. If it becomes too restricted, the engine will enter "Derate" mode, significantly limiting your horsepower and torque to protect the engine.

• Face Plugging: If the engine is burning oil or has a faulty EGR valve, a thick, oily layer of soot can form on the inlet face. This physically blocks the exhaust flow and cannot be fixed by standard regeneration.

• Fault Codes (DTCs): * Cummins: Code 1921/1922 (Soot level high).

  • PACCAR: P1496 (DPF restricted), P1495 (Regeneration disabled).

• Excessive Fuel Consumption: Because the engine has to work harder to push exhaust through a clogged filter and performs more frequent regens, your fuel economy will drop noticeably.