This port is shown to be used for the vacuum source for the fuel pressure regulator in the FFR Coyote instructions. As seen in Dale's photo, this port has a molded in plug with a 5/32" hex protrusion. I tried several ways to remove it and all failed. I twisted off the hex protrusion trying to turn it. In the end I drilled through it with a 1/4" drill bit. It was very thin and what debris fell into the intake shouldn't be a concern as it is plastic. There may be many Coyote builders that think they have a vacuum source for the fuel pressure regulator that don't.