The DPF filter (Diesel Particulate Filter) is one of the new solutions applied in diesel engine cars aimed at reducing the exhaust gas emissions. The filters have been installed obligatorily since 2011, which means that most of the cars produced a few years ago will soon have to undergo the DPF filter change. The DPF filter replacement procedure is very similar to that of the catalyst or a silencer. The filter itself, however, is very expensive and may costs up to a few thousand zlotys. You can try to replace the filter on your own, however, it is against the law to do so and you risk wrong data being fed into the engine computer causing its malfunction.