1999 Daewoo Leganza Gas Gauge/Gas Tank

I had the same problem....You may also have a pesky check engine light too. The gas level sensor attached to the fuel pump may very well be the problem. It is easily accessible by pulling up the back seat. Since you will be working around the gas tank observe all safety precautions to avoid sparks and work with disconnected battery and clean around it to keep dirt from falling into the tank. Look at the other end of the level float once you pull the pump out of the tank (about 10 minute job). You will see a small resistive electronic board at the pump end of the float. Carefully remove the retainer that holds the wipers against the board. If it looks dirty, take some very fine steel wool and lightly wipe the small strips on that board. You may also need to slightly bend the tabs on the contacts to ride more firmly against the board. Reassemble. Clear codes with OBD2 reader. Hope this helps somebody....it drove me nuts trying to find why the gas gauge didn't work....but more importantly, why I couldn't get that service engine light to go off.