It sounds like you might have some slug in the oil return holds on the heads. You might want to pull your valve covers and do an inspection. I had that issue with my Montero.
I have no idea how to do that. I mean, everything is running good. No knock, etc. Do you think this because of the PCV valve issue or because of the VX taking more oil or both? Could changing the EGR valve have anything to do with this?