Where does the pcv empty? If into the breather I would take it out of there and put it to a positive vac port. I may even take the pcv out and run a direct hose to a vac port. Several Jeeps I have had I put BOTH hoses from the valve cover to a vac port to stop the internal pressure...it worked fine. Also that breather may be clogged replace it with new or soak it in gasoline a while to melt the crud inside it.
Big Jim

professional bovine relocation specialist