First off, my car is an S4 N/A

Alright so I DID search already, but there were way too many differing opinions, so I was hoping some people could give me their opinions or experience with this. I did the "rats nest" removal along with all my emissions, thus the PCV came off with it. Now the oil filler neck had a ventilation (I believe that's what it was) tube that used to go into the the PCV. Is it okay to leave this venting to the atmosphere? I've seen the diagram of the S5 TII where it is said to hook it up to an oil catch can with a breather on top, along with another line besides the one on the filler neck. After searching, some people capped it, some people left it venting to the atmosphere, some people ran a line farther down to vent, some people put a little filter strait on the filler neck nipple, some people put in the oil catch can, but what is the right thing to do? Seems like everyone has their own "opinion" on it after searching, but I haven't found a whole lot of consistency. Sorry to have to ask this again

 

Well You need it open due to crankcase ventillation.

Most will either put a filter on it or do the right thing and get a catch can.

What happened is when the engine is breathing in there it can cause a mist of oil and vapors. The catch can obviously catches these and prevents your engine bay from becoming very messy. Almost every race track(1/4 mile etc..) will require you to have this.

www.1300cc.com has a home made catch can write up.

 

here is a pic of where I relocated my PCV on my TII engine aftr I removed the rats nest.

 

Ah ok, I see. Some of the past threads that I was reading made it seem like you absolutely shouldn't leave it venting without a catch can, so I was confused as to why. I guess it was all to keep everything clean and no dripping oil.