Description: The fuel tank gas cap prevents gas or diesel vapors from escaping while the vehicle is in operation. By doing so, it reduces vapor emissions and aid to fuel economy. It provides a tight seal ensured by a clicking sound once it is closed. If your vehicle is experiencing a Check Engine Light (CEL) and a code about EVAP leaks, gas cap wont click when closed or it is simply worn then you have to replace your gas tank cap. Features: Easy installation The fuel tank cap with smooth operation is easy to install,drilling,dismanting and adding are not needed. high performance .