My 2001 BMW 330i is losing a lot of oil and the car is shutting off when I put it in drive.

There is baffling in the system to prevent it from sucking up too much oil or the PCV is stuck open. It does not take much to suck oil into the cylinders if the baffle box, located at other end of PCV hose, has been damaged or if the PCV is stuck open. You can take the PCV and shake it to listne if it is moving freely. Somehow oil is getting sucked into the cylinders and stalling it and if it just started right when you got the PCV replaced it is most likely related.

It is possible that the PCV hose is dis-connected at the engine block which is near the rear of the engine, you can trace the hose, and it is leaking oil from that. The other problem would be a tremendoes vacuum leak that would affect performance tremendously and the computer would do odd things to try to compensate and it would probably make the situation worse.