I have smelled gas for some time and the other day when I parked the car, I noticed a large gas stain coming out of the car's gas tank lid. After spending some time cleaning the area... I didn't think too much of it thinking it was my fault that I have not closed the lid securely or not. Anyways... today I smelled the gas again. Althought it didn't leak out as much as it did last time, I noticed the rubber around the cap is wet and soaked with gasoline. I have no idea why. When I unscrewed the cap, it made a hiss sound from the pressure. Could this be a bad gas cap? or somehting bad? I am planning to do a roadtrip May 9th from Columbus to Chicago and would like to know what to do soon so I don't encounter a problem on the way and end up being stuck in some remote part of the country. Thanks in advance!