Rad fitted, front back on the car, plugged in and got 5 codes that all relate to the small drive without the pipe on the doser. Checked the 2 butterflies in the actuator test, fine. Test drive was fine, replugged and got 3 codes, first, couldn't connect to the bsi and 2 remote ecu messages. I haven't cleared those. I remember seeing those before and they vanished on their own. Off out this afternoon so I'll plug in again later. Definitely not a regen issue, as last regen was the previous journey before the damage. I'm beginning to think that I hadn't tightened the jube clip properly and over time it had worked it's way off. If it was tightened fully then I wouldn't think it was possible for the clip to get over the flaring on the entrance to the doser. Will keep an eye on the position of the pipe over the next few journeys as well.
Thanks again for all the info. above.