Just a bit of warning , when you do remaps things can go wrong and if you do it long enough they will so you need a backup solution. I have not touched A8 yet, mainly because I was still testing my new FGTech Galleto V4 54 to make sure it works OK and to reduce the chances of bricking A8. So well obviously I did brick the ECU on A6
but that's what the stress testing is all about. I am not sure what went wrong, I switched EGR back on, did slight adjustments to start of injection (SOI), fashed file - no start, no connection to VCDS, no connection to Galletto. The reason I chose Galletto was because my old Galletto 1260 was working just fine but it was a bit old and while it could do 4.0TDI dual ECU it could not do 4.2TDI, at least not officially, so I went for newer version. I am not sure about MPPS but I was led to believe that MPPS can only do master ECU through OBD so you either need to do them on bench or swap the places to do slave ECU on 4.2TDI with MPPS, but that can result in another problem with both ECU's thinking they are masters so you end up with only 4 cylinders running. Galletto 4 V54 will do both ECUs correctly over OBD. But what I found out was that if something goes wrong and you need to recover ECU in bootmode Galletto can only read it, not write new(or original) file even when it is in boot mode and on bench so I got myself MPPS as well. It's all good ECU has been recovered on bench with MPPS and it runs fine now, just a thing to keep in mind if you are going DIY route. I am playing a bit cautious as I can afford A6 being out of action couple of days but I really need A8 working every day.