I removed my plastic hose from the valve just under the intake for the evac system and had my son with his home made e-cig blow some smoke into the hose and I found my big leak,its a rubber hose that connects the rear to to the front plastic tube just in front of the passengers door hinge.I have not taken it for a drive but I did let in run in drive way and so far no codes.

 

Wow! I might have to buy an e-cig and try it out... Getting the P0455 code on my 01 S80 T6 as well.

 

https://volvoforums.com/forum/volvo-...2-p0455-59140/