the rollers could well be out and/or its a very good engine you have thats running well so i wouldn't go on the actual figures just the difference between before and after. bet it goes a bit nicer now.

dpf's are fucking stupid idea and they only seem to cause problems on modern diesels. they are supposed to help reduce emmisions but you'll find that when they start to clog the ecu dumps more fuel in to help burn off the crap in the filter to regenerate it. this is rather counter productive. also, in the owners manual it will probably say the car needs to be driven for 15 mins or more at regular intervals at high rpms to help clean the filter.

you're better off without the fucking filter

you can legally remove the filter but you may find it lacks in performance due to the low back pressure telling the ecu to under fuel a bit. his can be sorted by a propper remap. certainly thats what my mate found on his mk7 fez zetec s tdci though at first noone could crack the ecu so e had to run 2 tuning boxes. one for upping the fueling low down in the rev range and one for high up the rev range as one wasnt able to cope. i know shite solution but i think its all been sorted now with a proper remap.