1997 firebird

My initial suggestion is to pour a can of seafoam in the fuel tank, run that for a few days to loosen all the gunk in the system and get it moving. All the stuff it loosens should get caught by the fuel filter. Then replace the fuel filter. After that, once your gauge is sitting on the 1/2 mark, pour another can of seafoam in it, run it until the 1/4 mark, then fill 'er up. Just a little tidbit on the 93-02 Firebirds and Camaros, the way the tank is shaped means that when the fuel gauge reads over the Full mark, it's full, at the Full Mark is about 3/4 of a tank, 3/4 mark is half a tank, 1/2 tank mark is about 3.5-4 gallons left, and on E means find a gas station now.