It's called pat fluid. Gsf sell it for about 60 quid a litre. I had one a few weeks ago. Filled it. Reset values and confirmed it was full with diagnostic. Did a static re gen also. Code came back 2 weeks later. Customer ended up getting the dpf removed and re mapped. Cost him 400 and said car is driving better than ever. Only issue is nct will start measuring soot particles in the next few years so if your holding onto it have a good think about it
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