Where does the hose from the pcv valve run to on a D16y7? I keep thinking into the intake pipe that's before the air box but I'm not completely sure. And does anyone know if having this vent into the open would cause any problems?

 

Item 3 below is the PCV valve.

 

Thanks the port on the manifold is actually plugged off.

 

I expect your miles per gallon will be worse without properly venting the crankcase (oil vapor) to the air intake (via the PCV valve). Wherever you vent the PCV valve may get kinda oily.