Twin pumps

So I doubled up the pumps in my tank and had to eliminate that silver canister with the reg on it. Then
there's that brown one that's hooked to the bottom of the tank lid. Does anyone know what this stuff is for? Now I'm getting a tighten gas gap light.

BTW I did this at the same time I switched to return style.

the black plug on pump is the 'pressure sensor'. Not sure if you kept that intact. Either way, SHOULD be able to turn it off in tune.

Might have to I kinda messed up the little rubber gasket that's on it. But it's still in there.