As a general rule of thumb, if something happens after you touch it you probably caused the issue. As far as new parts go just because something is new doesn't mean it's good. I'm your case I would do what Scotty said and check the vacuum lines.  Go back and double check your work and make sure everything is installed properly. I've seen people many times forget to hook something up causing alot of issues.

It just happened after an OEM PCV Valve change. 

Then you need to go back to whomever changed your PCV valve and demand they redo it, if you didn't change the valve yourself. If you did it yourself, the vacuum line or lines aren't on, all the way. 

Jeff, it runs fine and you don't care. I would check for vacuum likes. No change the PCV valve. Sometimes it's just that and that's a simple fix