Oxy (non)Sense & Multi Funky switch

[dsims@axtek.com (Donna Sims)]

Doing some PM on my Audi 5kCSTurbo.

Anybody know what size socket (wrench) the stock Oxy sensor takes to r/r
it? Just bought a new third party unit ($81) and can't tell if takes
same size wrench. I'm guessing 17mm? Yes? No?

Also, bought a multi-func switch. Any special sealant or ?? to install.
Got it from Linda@Carlsen. Her prices continue to beat what my friend in
a dealer parts department can get them for, from Audi. Great sense of
humor, too.

TIA
Don S.