STP Diesel Particulate Filter Cleaner is designed to remove soot particles and carbon from diesel particulate filters. One treatment helps unclog filters, removing accumulated unburnt soot to regenerate the DPF, perfect for stop/start driving styles. It removes soot and carbon particles from diesel particulate filters and can help unclog filters, removing unburnt soot and regenerating the DPF. Specialist eBay oil & fluid seller with no leak guarantee.