http://www.audizine.com/forum/showth...ntake+manifold
Check this thread. If your intake manifold has started to fail but not to the point where the air flapper is jammed out of position you could get the codes and symptoms you have.
To rule out the PCV you can also disconnect the hose that goes from the intake manifold to the PCV and cover the intake manifold with a thick ziplock bag and reinforce it with tape. If this fixes the rough idle and codes then the PCV is leaking too much air into the intake. I have also heard of a failing rear main seal (allowing more air into the motor and into the PCV ) cause issues as well.