Turned my 06 GT on today and the fuel gauge started to bounce back and forth then stuck on E. I just filled it up yesterday. Now every time I turn the car on its good or a few seconds then goes to E. Check engine light came on and I got this code.

P0463
Fuel level a ckt high input

 

I would try some fuel cleaner, maybe you just have crud built up on the sensor. find a Chevron to fill up at next time.