Flaring Afro

My 98 Trans Am has been in the shop for a week for fuel pressure issues and the shop is stumped. I don't know all the details, but they changed the pump with another oem one and the pressure is fine right after the pump. At the fuel rails, it's only getting 1/3 of what it should, if that though. They said they replaced the filter and did an air test in the lines to check for clogs and the pressure was fine at the fuel rail side then. Is it possible the car has leaking injectors or something? I'm not sure what to do at this point other than take it to the Chevy dealer if the shop just can't figure it out, but that's going to be a lot more money.