I saw a thread a few days ago but didn't want to take over the thread. My gp gauge would move over the place then periodically, it would eventually settle on the correct reading. When the fuel was low it pretty much worked correctly it would stay on E and illuminate the light.
I went ahead and changed the level sensor and I noticed every time I started the car it would read full, and after a few seconds it would slowly go down to E.. The fuel was low when I changed it so I figured it kinda worked... I went and put a few gallons in and it still sits at full and then slowly goes to empty.. I guess its possible I damaged a sensor on top when hammering it back into place....