Tstealth32

That's exactly what the oil inside my catch can looks like. I'd much rather have it in the catch can than on my valves.

EHLO

We're in agreement there, any hint of oil in the post catch can line?
Here's Tstealth32's thread for reference;
https://www.audiworld.com/forums/a8-...2-fsi-2934038/

EHLO

Sludge forms when condensation mixes with oil vapor;
Blog Post Catch Cans 101

However, a catch can heated by the car's coolant prevents that;
Universal Air Oil Separator-Return (AOS-R)

EHLO

Replaced the exhaust Y pipe flex sections with 1 5/8" SS bellows January 2018.

The SS bellows type will last forever, while the SS mesh (like OEM) will wear out;
https://vibrantperformance.com/catal...433925b48b0bc5

I had to import the 1 5/8" size for the S8 from Australia;
https://www.aeroflowperformance.com/...?q=AF9500-1625

EHLO

Replaced the center resonator section with non resonated Supersprint pipes, Turner currently has them on sale;
https://www.turnermotorsport.com/p-351953-tms351953/

In place of the flex pipe section, it uses a half ball joint with compressed metal half ball gasket.
The three bolts holding it to the Y pipe had rusted away, so it was easy to separate, but it comes with replacement Y section flanges in case they need to be cut off.
Noticed that the stock X pipe only has an opening the size of a quarter between the two sides in a blanking plate.

EHLO

For sale;
https://www.audiworld.com/forums/market/3063912