Okay, so I've established where my mystery vacuum pipe goes but this morning managed to find out that at no time at any rev setting is vacuum present on that pipe at the pressure regulator. I dug into the underside of my intake manifold and got the ICV out, it's been cleaned by someone and the grommet (?) that it fits into looks quite new, I also managed to see where the CCV is....oh heck how do I get that out? As the vacuum pipe going between the pressure regulator and the CCV has no vacuum or pressure on it I can only assume it's no longer connected to the CCV or it's split or the CCV is duff. Obviously I have to get in there to find out but is the CCV accessible without taking the inlet manifold off or is that the easiest way in? Should the ICV make a loud buzzing noise when ignition is on?