How do I get to my vent valve?

[luis_fonseca2]

I have a 1999 Subaru Legacy GT and it needs a vent valve. I was told it is located on top of the gas tank. I want to now if I have to drop my diff and gas tank to get to it or if there is some kind of access panel under the back seats or in the trunk or something. Thanks

[alansgarage]

I have not noticed a vent valve on the gas tank top, but the tank, fuel pump, and fuel gauge sending units are all accessible if you put your back seat forward, open the trunk, and carefully pull up the carpet and mat right behind the back seat. There are two caps, slightly domed, and held on with screws. Access is under the caps.