DPF — sel Particulate Filter

A diesel particulate filter (DPF) is a wall-flow ceramic monolith fitted in the exhaust system of modern diesel vehicles to trap soot before it leaves the tailpipe. The ECU periodically runs a "regeneration" cycle that injects extra fuel post-combustion to raise exhaust temperature high enough to burn the accumulated soot into ash.

DPF systems fail in two predictable ways: regen failures (engine never reaches required temperature, soot keeps accumulating) and physical clogging (ash buildup over 200,000 km). When regen fails repeatedly the ECU triggers DTCs like P2002, P2453, P244A. Tuners patch the ECU to disable regen requests after the customer physically removes the DPF — for off-road and motorsport applications.