Begin with pressure plausibility
Inspect pressure with ignition on, at idle and under controlled load. Check hoses, routing, condensation and sensor offset before assuming the filter is blocked.
Temperature and regeneration
Exhaust temperature sensors must respond plausibly. Incomplete regeneration can be caused by thermostat, glow, injection, boost, EGR, sensor or driving-pattern issues.
Find the soot source
A repaired or cleaned filter will load again if the engine is producing excess soot. Air leaks, injector correction, oil consumption and boost control deserve attention.
Legal responsibility
Road-vehicle emissions systems are regulated. Repair the fault and follow the requirements of the vehicle’s jurisdiction. Specialist calibration is considered only for declared, legally permitted applications.