Gas leak

[Jimbeau]

I'm about to go work on a 98 Corolla with a gas leak. It's my Mom's car, so I haven't looked at the car yet. She had the same problem a couple of months ago. At that time, the local dealership replaced one fuel injector for $300. I don't know if they botched the job or what. Do the injectors go bad and start leaking? Or are there O rings or seals around the injectors that typically leak on these cars? I'm also wondering if the fuel pressure regulator could be bad causing too much pressure to the injectors. I'm doubting this is the case though. Thanks for any help. This is my first post here. I drive a 4x4 Taco myself.

[Nismo Convert]

Could be a leaky pulsation dampener, it's on the fuel rail.