06 Mercury Milan-Loose Gas Cap

http://cdn5.tribalfusion.com/media/37536.gif (http://a.tribalfusion.com/l.click?clickID=aOmyv7pGrwmtQA3aY72WZas5PBGnbjZcYs r0Xsn4Xs7nmEfR2rFWTFbCVAYWRqY3PGZbpPWFs1dvoT6Mp2V3 UXUrAU6io4PBeRmrK2tQr0dJJpdTM5mUS5GrgTGYcUVjjPAJvU tM3YG7hcb0kSO&clickURL=http%3a%2f%2fa%2etribalfusion%2ecom) http://a.tribalfusion.com/i.ad?site=AutomotiveForumscom&adSpace=CustomCampaign&size=300x250&requestID=1416317259 (http://a.tribalfusion.com/i.click?site=AutomotiveForumscom&adSpace=CustomCampaign&size=300x250&requestID=1416317259)My check engine light went on because my gas cap wasn't on tight. It will be 2 weeks tomorrow and the light is still on. My manual says it's suppose to go off by itself in 3 driving cycles but it hasn't. Does anyone know if I need to bring it to the dealer to have the light turned off or is 2 weeks not an unreasonable amount of time, and I should just be patient and wait a little longer. I hate driving with that light on! Thanks!

Take it to autozone and have the codes read. They read the codes for free.