thanks for your response unfortunately i don't have a cat back pressure gauge so i can't manually check the dpf pressure as for the dif. pressure sensor i have never seen it so low this car belongs to a member of my family and i have been checking it and logging live data for 4 years and i have never seen under 90mb at 3.000rpm even just after it had regenerated. this is a bit confusing to me as the dpf fault code is current and will not clear yet the mil is off and the car drives well only sometimes the message exhaust filter risk of blockage shows