93' Si, d16z6 with a ebay short ram intake from p/o.

Few questions. When I was doing my last oil change I noticed that the small air filter sticking off my engine in the picture had some oil on it. That kinda lead me to notice the hose that I pointed out with the blue arrows isn't connected to anything. It looks like it's supposed to be where the red arrow is.

What's the purpose of the little air filter and should I leave it on instead of hooking the, currently useless, hose up to my intake pipe? If I should leave the little filter on, should I plug the red arrow hole up?

Why would there be motor oil all over the filter?

WTF is the (green arrow) plug for? I'm guessing it's for an OBDII sensor that I don't need?

 

The best thing is to take off that filter and use a rubber hose that connects the valve cover to the hole on your intake(red arrow). The hose that you have there unplugged (blue arrows) originally served that purpose but plugged into the stock air box. If you don't want to do that, plug that hole up.

That electrical plug is (green arrow) for the IAT (intake air temperature). I believe that is just for OBDII.

 

So is it worth going out and buying a piece of rubber hose or am I good with the little filter that's on it right now? Also, why's there motor oil on the filter, should I be concerned? lol

 

Its fine the way it is. The filter is just a breather filer. That metal tubing goes in the factory rubber intake pipe, not airbox. And the oil is normal seeing as the pressure being release from the valve cover is exiting from that filter, and you have oil inside your valve cover... You should only be concerned if oil quits coming out lol, its not a lot of oil that exits. As far as the intake air temp sensor, its not something that absolutely has to be in the intake, but it wouldn't hurt putting it in.