So I just installed a walbro 450 fuel pump and followed another forum on here on how to modify the OEM housing and we put it all together but when I was fueling my Evo at the gas station on the trailer, I heard fuel just falling onto the trailer, what could be the causes? I checked the connectors and lines on top of the housing and wasn't leaking.

 

Are you saying you have a fuel leak?

 

The rubber O-ring where the fuel pump housing is, needs to be put on correctly. If its not seated properly gas will come pouring out on the ground.