Are you looking for information about DPF replacement and how DPF filters works in practice? Visit the blog which is also dedicated to this. Blog about how DPF works you can find here. If you are interested in more specific solution in your case or eventually you are looking for information exactly for your brand and model of the vehicle, so try to look directly at forums on the various brands of the vehicles. You will find really a lot of information on this topic and feel free to ask on the forums.
Vehicle emissions control and fees in the UK
If you have purchased a vehicle registered in England, you have to pay the insurance and motor vehicle tax, based on emissions produced by the vehicle. The calculation of the fees are not based on data listed in the vehicle registration certificate (log book). As an constitutive indication for officials is final statement from the technical inspection. Officials after that, based on real-time status of emissions production, calculate the amount of fees that you have to pay as the vehicle owner. You could say, the worse condition your vehicle is and the more you neglect the maintenance of your vehicle, the higher amount you will pay. From this point of view, the owners of vehicles in England are motivated to keep their vehicles in the best condition.