Failed gauge, wiring, or level sensor.
The gauge or sensor needs to be replaced.
check your ground wire to the gauge
check your answer
I would assume that the wires are hooked up backwards
My 2001 had the same problem. There is a GM recall to replace the sending unit.
Assuming you mean gallons of gasoline, the fuel gauge may not be accurate. It may read empty but in fact it may be still half full.
Where is it stuck? on full or empty? if on full you got a bad ground, if empty you got a bad float.
Either the gauge is broken or the sender is broken.
Your fuel sending unit is not giving the correct reading to your gauge
you should go to a car shop for that one!:)
fuel sending unit broken wire or gauge is bad
the fuse my be blown or ,it needs anew gauge