Sorry this is a little late
You wont find a direct part number for that as you have to buy the whole intake tube assembly to get that little breather.
I just went to Autozone and bought a PVC valve similar to this
Motormite/PCV Valve Elbow (47032) | AutoZone.com
and just reconnected the hoses, I have had no problems after 10k+ miles.
I would also suggest going to a junk yard and pulling one off of a 350z, as they have this same part. Nissan still wont sell it alone, 350z or 370z you have to buy the whole assembly.