I have an '06 XC70 with ~80k miles, and for the past few weeks have had the two codes recurring on my car. I'll reset the codes, drive 20 miles and one, or both of the codes will come back. The two codes are:

P0496 - Evaporative Emission System High Purge Flow
P0497 - Evaporative Emission System Low Purge Flow

Recently I replaced one of the hoses in the car as there was a significant vacuum leak and the car was idling very rough and throwing a variety of codes (P0300 - random misfire, P0101 - Mass air flow performance problem, P0507 - idle RPM higher than expected, and P0170 - fuel trim malfunction). Replacing the hose resolved these issues, but now I am getting this.

It seems that replacing the purge valve is the best bet to resolve these codes, but haven't seen much on either of these two codes for Volvos. Does this seem reasonable? It seems like an easy to do job, but does anyone have any diagrams or have a location on the purge valve?

Input and thoughts are greatly appreciated.