I know that it is possible to disable DPF (Diesel Particulate Filter). I'm wondering how bad it could be to leave DPF (Diesel Particulate Filter) functioning and add a chip to a car?
In the UK it's common that people have a "DPF Delete" from their engine map which can improve performance at the cost of the vehicle no longer complying with emissions standards. There seems to be no adverse long term effects on the vehicle over those with the DPF in place with the exception that they can consume clutch packs after fewer miles if driven hard (which relates more to the extra engine performance placing more strain on the part than the actual DPF removal).
There is a rolling road remap place behind my house and I regularly see all kinds of cars having a DPF delete carried out (curiously few Volkswagens though - as the DPF delete is effectively what they are in hot water for with the American authorities right now).