2000 Jeep Cherokee GAS GAUGE

Sound like the gauge sending unit in the fuel tank is either stuck or bad.
Let's try something; When you know your fuel level is about a 1/4 tank or lower, take a baseball bat, rubber hammer or something similar and rap the bottom of the tank a few times. Then, see if the gauge reads in the lower range. If yes, the sender is probably sticking and will probably stick again over time. The sending unit is in the tank and the tank will have to be removed to replace it. Also, the bad part, I believe the gauge sender and fuel pump are an assembly and have to be changed as a unit. Estimated repair cost. $300 to 500.