Thanks for the photo. That's exactly the same as mine (3.0 BiTDI). Guess yours is also RH drive (in the UK)?
However, I'm pretty certain it's neither of those 3 connections into the exhaust. The SCR injector apparently has 4 attachments: 1 for the electrical connector, 1 for the Adblue feed and 2 other pipes (whatever they're for). See the attached pic.
I've put about 40 Ltrs of Adblue in over the last couple of months and done no more than say 3,000 miles in that time. Also been using the Wynns de-crystallizer each time in the hopes that might clear things up. The last time I put another 10 Ltrs in last week, the warning light disappeared but was back on again within only about 20 more miles.
Either there's a mighty leak somewhere or maybe the injector's stuck open (?). Inside the tailpipes looks clean & dry though.
Really don't want to put it with a dealer. Countless posts show they don't really know what the issues are either and will just blow your money replacing expensive parts like a new tank, injector, nox sensor etc and still not sort it out.
This whole Adblue issue is an outright disgrace. Audi should solve it and offer a free fix for ALL cars, even out-of-warranty.
I'm getting very close to an Adblue delete now. Would rather not go that way though. If I can finally find out *where* the injector is I'll try cleaning it as a last resort.