Battery and brake warning lights

The battery and brake warning lights came
on in my vehicle. It’s a 2001 Subaru outback.
I took it into the shop after getting the battery
replaced thinking that was the problem but
the lights were still on. The shop said it was a
fuel leak and tightened up the clamps and
said I was good to go. The lights came back
on and not even a mile down the road. They
want me to bring it back in. They said they
tested the alternator and it was fine. What
could it be? I’m afraid to take it back to them
because I never smelled gas before and now
I do.