i just pulled the intake upper and lower completly to change out my injectors and if i look into the 6 holes of the lower intake they are all clean and shinny except the one before the last closest to the firewall and it appears to be a dark color kind of like burnt oil. also i checked in the valley of the lower intake manifold and there appears to be fresh oil drops not alot but its there, as i just changed the oil yesterday and its clean so its not old oil. is this normal with the 350z as i am putting on my vortech and just trying to insure i have a good platform to begin with. the car is basically stock with 54,000 miles. thanks alot

 

Read this thread -

https://my350z.com/forum/engine-and-drivetrain/188315-very-simple-oil-catch-can.html

 

even easier, put filters on your valve covers and remove the hose between the valve cover and plenum/intake tube. then plug the two holes up on the plenum/intake tube...

 

I don't want to seem overly ignorant, but what is the hose coming out of the back of the left valve cover doing. Does air get pushed into it, or does it evacuate pressure. And why isn't there another PCV valve back there as well? OK, I'm done.