An integrally molded carbon canister is provided. The integrally molded carbon canister includes a housing including four external side walls and an upper portion at least partially enclosing an internal cavity connected to a vapor inlet and outlet port, the upper portion including a depressed flow disruptor positioned rearward of an injection gate, and a first and second projected flow channel positioned adjacent to the injection gate and laterally spanning the housing. The depressed flow disruptor has a thickness that is less than a section of the upper portion surrounding the depressed flow disruptor and the projected flow channels have a thickness that is greater than a section of the upper portion surrounding the projected flow channels.