550rpm is really low. The new pcv should move that up to 700rpm? You could still go higher, 750-850 in P is correct. I set mine at 850 just because I like a higher idle.
A lot of blow by at high rpm driving could blow seals. Hopefully you’ve caught yours in time. But until any sludge is cleaned out of engine, i wouldn’t drive too spirited.
I had a car with a faulty pcv system, i ended up blowing out a cam seal. Fixed pcv, lots of oil changes with safe cleaners, within 6 months engine was good, never had a bad leak again.