I have a volvo xc7- turbo wagon. It is showing a check engine light. Someone read the code for me. PO442...."evaporative system..small leak". I have checked the gas cap and I still have the light. The light comes on when I accelerate briskly from about 20mph to 5 mph. Has anyone experienced this and know what caused it? Trying to find a pinhole in the evap. system is probably going to take a lot of shop time. TIA Arthur