TT engine cover

[yozzertt]

Hi all, new to the site and looking for some info. I changed my coils packs the other day (2008 TT 2.0 tfsi) and when replacing the engine cover, I noticed a small rubber pipe at the rear of the cover, around 2-3 inches long and about half inch in diameter with a tiny hole in the center. I have no idea what it is for, but I am hoping it was not connected to anything. I can not see anything there to connect it to so any info would be greatly appreciated. Thanks.