These can be reasons for a DPF not to regenerate. Ending Note. Whenever you feel like soots have built a home in your 6.7 powerstroke, force regen it. You will need 30 to 45 minutes only. Our steps are helpful enough to perform the regeneration process yourself. But a better option would be getting help from a mechanic. And don’t forget to
After the engine has sufficiently warmed up (engine coolant temperature of 80 °C (176 °F) or more), depress the accelerator pedal and drive the vehicle at a speed of 20 km/h (12 mph) or more for about 15 to 20 minutes to eliminate the PM. When “DPF malfunction” is indicated. Contact an Authorized Mazda Dealer. DswrJS.