hey all,

i have an 88 S4 FC EGi (uk model n/a)..was on track and seems as if something popped from the engine bay, i can see where but i don't know what was there before and need a little bit of help so that i can replace it!
it looks to be something to do with the acv system, it may just be a hose, but need to know for sure in case theres seomthing else there instead..
heres a pic, its fairly clear to see soemthing is missing between the two pipes.. so if anyone can tell me exactly what it is, or ideally show me a pic aswell (have done plenty of searching but cannot find anything) of an engine bay with this part intact that'd be fantastic.



car drives perfectly, is just a lot louder at the front..

cheers

 

Your air control valve looks a little different, but it looks like the relief pipe that goes to a silencer usually mounted under the pop-up light. When the computer says to the ACV no air is needed to the cat or exhaust manifold, it sends air to relief (atmosphere) and dumps the air via some hoses and silencers. Just connect the two pipe/hose. Rev the car a couple of times past around 4,000 RPM's and you'll see air coming out depending on load RPM. This is the jist of it, I won't retype the FSM here...secondary air injection system is more complicated than this...