well that little black box on the back of the block (not the black cannister on the firewall) on my 92 b16a seems to be leaking oil. can anyone tell me what that black box is and does it have to be replaced or does a gasket need to be changed? thanks in advance.

 

lol..nice pic..that is the pcv cannistor..replace it if its full or empty and clean it out

 

There's a round hole in the back of the block into which a round port from the box fits. There's an o-ring for that connection. If this o-ring were to corrode or get pinched, it will leak oil. Easy (and cheap) fix from under the car, though.