Hello? Has anyone used a gas sniffer like this to detect small fuel leaks? I have a hard to pin-point source of gas vapors in my recent RCR GT40 build. I think it has something to do with the fuel inlet tube to one of the gas tanks. I used a shop vac to pressurize the tanks and used my nose and the soapy water/bubbles test with no detectable leakage. It advertises that it works for fuel vapors, but, you know...Thanks!