Why does my P0457 code keep returning?

Although you have attacked the most likely and common cause of an evaporative emissions system vapor leak, the gas cap is only one possible cause of failure. There are many components in the system that can leak, and a static and dynamic test of the evaporative emissions system is required, including one that includes the use of a "smoke machine" that will add vapor to the system and see where it leaks out of in an effort to find the leak. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops