Outer Limits 4x4 Board

today while driving i flicked the switch to start using the gas injection and i could smell gas coming out of my aircon vent. so i turned the gas off and when i got home i investigated and forund it was coming out of a hose which is not connected to anything. can someone please tell me what it is and if its meant to be hooked up somewhere, im pretty sure it is a drain of some sort and meant to be how it is. im thinking its a teltail for a broken diaphragm

thanks in advance

IIRC, that line is a vacuum balance line. It should go to a fuel/vacuum switch that comes off the exit side of the EFI rail. And no, it shouldn't be just flapping around in your engine bay.