I always close the EGR is with or without dpf
Are the changes very difficult, I've seen them, but they are not within the reach of us mere mortals, in practice, lowered the threshold of clogging in km and in time, other times it's fooled the percentage of clogging that remains after regeneration. (this ? what I understood until now)
Any way to touch these parameters ? simple and the effects are seen in long-term...