I have a 1998 Grand Prix 3.8 engine. The Check Engine Soon light is on. The Code is P0441. I checked the purge solenoid valve (using car battery), it seems open/closed fine. However, when I use my mouth to blow the tube which connects the solenoid valve to the eva switch (or to the tube after the switch), the air can go through freely. Do I have a leak gas tank/tube or a faulty switch, or other problem?

Please help. Thanks