There's 2 nipples on the side of the intercooler, top one goes to the bypass air solenoid I think, and the other is suppose to go to where? .. FSM doesn't really show it.. and a googling found nothing. I'm pretty sure I need to cap them off because what they go to has been removed, but I wanna be sure.

 

it is called an Air Supply Valve, an additional load idle assist solenoid found on the S4 turbo cars. there is a nipple on the backside of the UIM facing straight up. if you have a JDM or late model S4 then it will not be there.

 

Usdm came with two additional valves compared to Jdm. One valve sits on top of uim and the other is behind it on the firewall side of the uim.