How do you fix gas gauge in 99 Oldsmobile?

To fix the gas gauge in a 1999 Oldsmobile, first check the fuel sender unit located in the fuel tank, as it may be faulty or have a poor connection. Inspect the wiring and connectors for any damage or corrosion. If necessary, replace the fuel sender unit or the entire fuel pump assembly. If the issue persists, the problem may lie with the gauge itself or the vehicle's instrument cluster, which may require professional diagnosis.