Need to know about ebay oil catch can
 

Need to know about ebay

I bought the same one for my spec v. Same problems with leaks. But additional to the ones you sealed up. I found out those shark bite looking 90* push in connectors didn't do much of good job sealing either. I think my clear tube was too short. I never fixedminer, just went back into a box for another day.
So do up actually leak boost thru the pcv valve. (I'm trying to think how it flows. Manifold > valvecovers > intake hose or opposite direction?)

IMO, those cans are just inadequate - they're cheap. Get an ADD W7 can, higher but are a lot of can for the money. I own three and run them on both 2003 Maximas as well as my 2004 Quest. I may end up running one on my '89 turbo too, but it already has a custom on that works exceptionally well.

As far as the recirculation system, it flows in both directions.
1. At idle, the PCV opens and pull air into the inane from the rear valve cover. Fresh air is then pulled from the intake tube and in through the fron valve cover, adding fresh air to the crank case.
2. At open throttle, the PCV closes and "seals" the rear valve cover. Air is pulled from the crankcase, into the front valve cover, and out through the intake tube which then get sucked into the engine. This process creates slight negative pressure. The purpose is to help the rings seal under load and higher rpms while also pulling out gases which contaminate oil.
- Once off throttle, PCV re-opens and the system reverses back to 1.

Great/accurate description of the stock system and why you shouldn't just slap a breather on the valve covers (no vacuum to pull dirty air/improve ring sealing). Just for the record, the ADD catch can logo looks a little like "W7" but it's actually "W1". Version 1 is sealed and version two has a hole with an optional plug to keep it a closed system or a breather that screws in place of the plug for an open system. Use the plug if you get version 2.