I own a Skoda Octavia 1.6i Ambiante y 2001

I have had a problem with the idle, where it is revving up and down on it's own. I had it tested the fault was the mass air flow sensor, so i replaced that,it is still hunting. I have also replaced two of the main breather's(yesterday 10 march) it is a little better, but the management light is still on.
I cant think what else to do or change. Could anyone throw some light on the subject please.