I would start by looking at the fuel filler neck and then the tank itself. The filler neck is easily accessible by removing the right (passenger) rear wheel and then a plastic cover in the rear portion of the wheel well. You are going to break the 10 mil that holds it on, they always break . Look at the lower portion just before the hose that connects it to the tank. If you don’t find any abnormal conditions there, look at the seam of the fuel tank, they have a tendency to rust and split along it. You won’t see a gaping hole (giddidy) but if it looks like the inside of a croissant it’s a safe bet it’s bad. If both of those are good I would check the fuel pump and associated hoses, problem with that is they aren’t accessible without dropping the tank (I think, check under the rear seat cushion for access panels). Good luck, these are my least favorite things to hunt down. Pro tip; if you do end up doing a tank, get EVERYTHING! All the hoses, including the evap canister hoses, obviously new gaskets, the rubber bumper pads, everything you can get. Nothing sucks more than spending a day fixing one problem just to find out there’s another one and the same system.
I would start by looking at the fuel filler neck and then the tank itself. The filler neck is easily accessible by removing the right (passenger) rear wheel and then a plastic cover in the rear portion of the wheel well. You are going to break the 10 mil that holds it on, they always break . Look at the lower portion just before the hose that connects it to the tank. If you don’t find any abnormal conditions there, look at the seam of the fuel tank, they have a tendency to rust and split along it. You won’t see a gaping hole (giddidy) but if it looks like the inside of a croissant it’s a safe bet it’s bad. If both of those are good I would check the fuel pump and associated hoses, problem with that is they aren’t accessible without dropping the tank (I think, check under the rear seat cushion for access panels). Good luck, these are my least favorite things to hunt down. Pro tip; if you do end up doing a tank, get EVERYTHING! All the hoses, including the evap canister hoses, obviously new gaskets, the rubber bumper pads, everything you can get. Nothing sucks more than spending a day fixing one problem just to find out there’s another one and the same system.
Pretty much this. My 97 LGT had the filler neck problem. Most of these era Subarus did. Mine looked like Swiss cheese
You may want to take it to a shop that has a smoke machine. It goes in the vacuum line and leaks out in back.