Hello and welcome.
What exactly is the fuel gauge doing?
OK. sounds as if you have a problem with the fuel level sensor in the tank. This is a common problem. The sensor is a resistor, and the "fingers" that ride on the resistor get corroded away and cause intermittant/false readings.
The fuel pump/sender with the level sensor is in the fuel tank and can be accessed through a cover in the trunk floor of the car. No need to remove the fuel tank on this car.
The sensor can be replaced seperately, and must be removed from the fuel pump/sender assembly after the assembly is removed from the fuel tank.
From in the trunk (or fold down pass. side rear of back seat if it has that oprion), you need to remove the trunk carpet on the floor pan. There is an oval shaped access cover, close to the rear seat back, just to the rt. of center.(see 1st.pic)
Remove that panel, then remove the electrical connectors and fuel lines from top of sender and fuel pressure has been released. Remove the entire assembly(Large snap ring), and replace the level sensor (see 2nd. pic #5)
Hope this was helpful
Sounds like the guides are worn out. Would need to be replaced as an assembly.