Outer Limits 4x4 Board

I'm building a false floor/storage compartments for inside the back of my sierra, and while stripping out the seats and stuff I removed a panel from behind the driver's side wheel arch that protected the fuel tank inlet hose. Mounted on the fuel hose is a little plastic bottle(like a little mini windscreen washer bottle without a cap) with two hose coming out of it and passing through the floor along side the fuel tank hose. Anyone know what this is and what it is for?? I followed the hose and found they went no where, one end was clogged with dirt. I want to remove this but thought I'd check to see if anyone knew what it's use was first..

as fuel evaporates, like when parking on a hot day, it condenses in that bottle, so it can be sucked back into tank later....better fuel economy and less harmful fumes into our air.. also the tank breathes thru that, as fuel is sucked out by engine, air gets back in via that bottle and the carbon cannister under the bonnet...if these arent plumbed properley, then dirt in tank, or air locks and other probs can ensue....correct fitting is top hose goes thru the car to the carbon cannister under the bonnet, and bottom hose to breather on fuel tank....I think its better to have these plumbed right, but car will run as long as it can get air back in...christover