A DPF is a device that is installed in the exhaust stream of diesel engines made after January 1, 2007 in response to more stringent emission regulations. Harmful particulate matter found in diesel emissions contain carcinogenic components that have been linked to adverse health effects. The DPF is designed to remove the particulate matter (soot) from exhaust of diesel engines. These filters can remove 85% of the soot and if combined with Diesel Oxidation Catalysts (DOC) can have even greater reductions. Your filter should be professionally cleaned on a regular basis. Western Turbo are the DPF cleaning experts.