DPF Efficiency Below Threshold

P2002 on a MaxxForce 11 (10.5L) (2008-2014) indicates: DPF Efficiency Below Threshold. This is a known fault code on the MaxxForce engine family and typically points to the causes listed above.

Only drive short distances to reach a repair facility. Continued operation may cause further damage or progressive derate.

Repair cost is typically $800-$5,000 depending on the underlying cause and shop rate. Many MaxxForce faults (especially EGR cooler, head bolt, and VGT repairs) are major expenses that drove fleet owners to repower with Cummins or retire these trucks early.

California's heavy-duty OBD regulation requires the system to flag the PM filter before its filtering capability drops — from cracking, for instance — enough to push PM emissions past 0.07 g/bhp-hr, or past the applicable standard plus 0.06 g/bhp-hr, whichever is higher (Title 13 CCR 1971.1, section (e)(8.2.1)). Where no credible failure could reach that level, it must instead flag the case where no detectable filtering is happening at all. This threshold comes from the heavy-duty OBD regulation, which covers 2010 and later heavy-duty engines. If your engine is in a pickup at or under 14,000 lb GVWR it is certified under the separate medium-duty rule instead, so treat this as the design intent rather than your engine's exact limit.