Does anyone know what this is and what it's function is? I've looked everywhere including the FSM and courtesyparts.com but cannot find anything. I'm thinking it is some kind of stock oil catch device for any blow-by that may get up into the intake manifold, but am unable to confirm.

 

Anyone?

 

Helmholtz resonator. GM_Traitor3.5VQ mentioned it on the forums before regarding an oil separator catch. Not a bad idea either.

 

I put a catch can on my Charger and emptied I at every oil change. I did catch quite a bit each time. However, I haven't seen one for the Maximas.