I have a '99 A6 which cuts out when i take longer than one second to change gear when i'm doing 30-40mph.
Also discovered that it cuts out at the same speed if i dip the clutch and hold it down for 1-2 seconds??? Causing problems when aproaching roundabouts and waiting to choose gear depending on whether i have to stop or can go straight away.
Any suggestions/solutions
Thanks

 

scan the ecm for codes

 

I am thinking air mass sensor? Fairly certain, actually. We had a Merc that did the same. Stalled at traffic lights, though. And it was an auto!