You should run your fingers along the PCV hose and check it carefully. They are known to crack near where it goes into intake manifold. I read about this on here and I checked mine. There was a long split where the hose curves. I replaced it and the engine ran much smoother.
i just replaced my pcv hose and the elbow it connects to on my 99 V10
was on the pass side vc
there are two hoses you will need
the pcv hose (has the valve in one end) and the elbow (hooks to the manifold)
total cost a around $25
cured my check eng light left and right bank lean codes
I have a rubber hose going from the driver side valve cover to the intake tube on my 04', I believe this is the PCV. here is also a tube on the passenger side valve cover with a corrugated plastic cover on it that looks like it goes to the plastic elbow on the intake manifold that the throttle body bolts on. My trucks an 04' F-250 V10 with no EGR.