Sounds like you have all the key timing features correct:
* #3 @ TDC
* lock pin installed
* cam lock bar aligned
* both Exh & Int cams centered on bearing cap alignment mark ( ^ )

Timing chain won't stretch...to any noticable amount.
Here's some other options:
* make sure your cam chain tensioners are installed on the correct bank. They look alike, fit alike, but don't work alike. Check p/n's for L vs R side.
* check the bank 2 cam position sensor (CPS) to be certain the little tab on it's end is assembled correctly to the slot on the cam end. Seems hard to get it wrong (tab into slot), but never know.
* cam tensioner shoes are on both upper & lower feet. With new tensioner, I'd expect you do. AND if not then prior cam alignment check would not align correctly, and it would make a racket while running.
* swap CPS btw bank 1 & 2. They are the same p/n. If code follows then you know it's a bad CPS.

 

I did the cps swap, no result.
I pulled both of the little cups off both cams to compare, they're identical. I ended up pulling the ecu connector to check for resistance and everything came back good.

I know it's something I'm doing wrong but I can't figure it out, still open to more more suggestions

 

Update on this....

Ended up paying something like $40 to talk to an "audi mechanic" on justanswer. I was skeptical about it but he told me to put 15 links between the two timing marks of bank 2 (adding a link).

Bobs your uncle, no more code

 

Well sounds like you had chain count wrong btwn the cam sprockets, so I doubt the cam alignment marks were lining up properly. In the link hxgaser referenced (Lexus SC400 Down, Audi A6 Up ), I included the correct chain roller counts, as I struggled through my miss fires issues.

Glad you got it fixed. $40 not too bad on the Audi cost scale.