there was a thread a while back that discussed the differences between the Nissan OEM PCV valve and aftermarket parts such as Fram. I was in an auto parts store yesterday and out of curiosity took a look at the Fram PCV on the shelf.

there is a clear difference in quality between Fram and OEM:

Fram ($6)
- sharp/jagged plastic "danglies" on body left over from the plastic injection molding process. these will get caught in the rubber grommet and PCV tube, resulting in difficult removal/install and possible damage to those rubber parts.
- irregular lead check ball used in the valve did not seal well, allowing blowby in reverse direction.
- lead ball may be more prone to deposit formation, and premature clogging of the valve.

OEM (can be had for $8)
- smooth plastic body free of any "jaggies"
- plastic valve fits nicely around inlet with a smooth spring action. good flow in forward direction, tight seal in reverse.

My impressions of the OEM part are based on the original PCV on my '99 w/over 93k miles on it. the part is still in service and in perfect condition, aside from a slight bit of discoloration on the valve cover side.

my advice, if you are going to change your PCV spend the extra few bucks and get an OEM.

 

Thats exactly what i did, wanna c pics comparing my old and new PCV valve ?