Gas meter stopped working on 04 Corolla with 136,485 miles on it. Why?

More then likely the fuel level sending unit in the fuel tank, if you know how to test the gauge to be sure the gauge is good, if not have it tested first to verify.

Also.....It' a fairly easy one to test 'IF' one knows how! Got a car nut for a buddy? It's under the back seat, easy to access for testng. But skill is a must!! This is rare for this car but it's possible,,,,,obviously!