Installed a fuel cell in my trunk on my 67 Coronet. All is good but I smell gas. It is vented but at this time it is just a straight hose out of the tank through the trunk floor. I am going to get a longer hose so I can loop it but also wondering about a roll over valve and some sort of an attachable charcoal canister? to help stop the fumes smell. Is there such a piece that would work as both a one way valve and fume stopper? Thanks.