Amazon.com
LEFT
OEM Ref No: 078 109 087C 078 109 087F,$245.00 "left" Factory List Price is $609.93
http://www.amazon.com/Tensioner-0781...=pd_sbs_auto_1

RIGHT
OEM Ref No: 078 109 088C 078 109 088H,$255.50 Factory List Price is $609.93
http://www.amazon.com/Tensioner-0781...=5336121816-20

Vast
OEM Part #: 078 109 088 C passenger $499.99 !!!!really!!!!
https://vastperformance.com/index.ph...nger-2-7t.html


THE DIY and BTW the passenger is 15 links driver is 16 from what I understand
https://www.audiforums.com/forum/sho...d.php?t=101340

 

I dont have my manual here in front of me but you count the same number of links on both the drivers and passengers sides and I beleive it is 16. The reason you hear of 1 link difference from the drivers side to the passenger is due to the way the drivers side intake cam timing mark is stamped. The timing mark on that cam is stamped on the peak of a tooth and not a valley so technicaly it could be correct on either side of the mark as you cant line it up exactly on the 16th tooth. Be sure when you line up that tooth that you do so with the mark to the left side of the tooth if you are standing in front of the motor looking back. The car will run fine with it lined up on either side but if it is lined up to the right side of that peak the ecm will kick a code for improbable cam position. I learned this one the hard way and had to tear mine back down to move the chain one tooth to resolve the code issue.

if you do a little searching over at Audiworld there is a nice write up with good pics about this issue.