2 weeks ago, Pam was fueling up the Tahoe, filled it up as far as it can go.. smell of gas is very strong, nothing differenct in the way fill it up.. A customer stops us, points to the ground say's your loosing fuel.. Look underneath (has body lift.. makes it easy to see) and the upper most part of the gas tank has a sensor/ 3-wire connector up there. Gas is leaking out of it.. can't stop it so we don't overfill it anymore. Does anyone know what this is? I unplugged it and started the vehicle.. no difference in starting/driving/ etc.. I did find the plastic fitting broken.. its not secure... any idea? Part? what is it? How to remove it? and what does it do?