Is this correct? Because when I looked this issue up it said if it idles fine the valve is on its way out.... So if it idles rough its meant to be working right.
You will know when the PCV is on its way out cause you will loose manifold pressure and you will be able to hear it squealing cause the gasket on it is rubbish. Just a personal note too I wouldn't be putting any aftermarket engine cleaner through a VW cause they reject any and all products that are not genuine like a bad kidney.