2009 VW CC 2.0 T rough idle and whistling engine fix

This 2009 Volkswagen came in with a  fluctuating idle, revving, high and low rpm’s almost to the point of stalling out, as well as a whistling sound coming from the engine bay. I pulled the vacuum hose off of the PCV valve and placed tape over top and you can hear the difference of the engine running and then replace the PCV valve for a cost of $35 and it fix the problem. I hope this helps everyone .