this has issue has plagued me for a fair few months now and have tried all sorts to fix it:
maf, sparks, coils, new intake (itg), replaced oem 'd' dv with forge dv, and also replaced my miltek downpipe when that blew a hole in the flexi flange
problems still remained - mainly in 4th and 5th gears and c5krpm, boost gauge suddenly drops from c20psi to 5-10psi for a second and then back to full boost
only solution i have found is too turn down the settings - i used to be b8t6f6 and am now b8t5f7
with the new settings the car does not stutter,
interestingly i noticed if I turned the timing up to 7 then the issue got worse and the stutter happended twice in the rev range
i am a vagcom beginner but this is a log i did at t7, can anyone advise what else i should be looking for