Audi=No fault code, no idea
I wouldnt worry about it, if its just a snatch on take up and shows non of the other synptoms on Sarah's link then its just the nature of the beast. Mine has done that for the last 30k miles. It did get better after the remap but it also is worse when its cold and after about 30 miles is almost fine..
It hasnt got any worse since i have had the car fron 12k miles to 48k miles.
Ibis white Revo S3 and now matching Vivaro LWB HR 2900 :-)
Many people are alive because its illegal to shoot them.