The hose attachment is part of the whole engine flush kit. If you are not able to find it online, you might have to purchase the whole device. They aren't that expensive.
A solution for one problem is to spray carburator cleaner into the fuel line going to the sensor. When this line gets clogged it will not read correctly.
Sometimes when a boat is waxed, excess wax piles up over the fuel vent opening inadvertently. The solution is to visually check this out and clean it up. If the vent is free and open, that should solve the problem.
I believe there is supposed to be an "O" ring around the quick disconnect male. There around but hard to find. Bring the plug when you go to the hardware store.
