No error codes for the PCV system. It is past time to replace the oil separator system. Quite possibly, the hole in the bottom of the crankcase to the oil separator box is clogged. If so, reaming it out with a screwdriver will be required. The breather hoses are old and tend to crack when moved, so they need to be replaced as well.

The high crankcase pressure will blow out the cam seals if you are lucky. It can also blow out the RMS which is a ton of work.

There are several procedures online that explain how to replace the PCV hardware. Your non-turbo engine is not that difficult if you remove the engine fan first to get more knuckle room. Remember, the bottom bolts for the manifold only get loosened, not removed. And, there is a support bracket under the manifold that is invisible, the top bolt must be removed before lifting.

There is also a method to just lift the manifold and pivot it up and rest it on the top of the engine so the fuel lines do not have to be disconnected.