Fuel Light Flashing and Showing Empty

[EOT1]

I have a question. I have owned my '99 996 C2 for about 2 years. I took it in to Stuarts Paint in Dallas, Texas to have the front bumper cover replaced. When I got it back, the fuel light was blinking and it shows empty. It was not like this when I took it in to be repaired. I know this can mean the fuel tank pressure sensor is out. I have the Durametric software to reset any/all codes, but the error continues to pop up. What should I check before replacing the pressure sensor? Any advice is greatly appreciated.

[LanceGT4]

The shop probably disconnected the battery while they worked on the car. Try adding some fuel. I've never had the blinking light but my gauge will always be off after I disconnect the battery.

[BYprodriver]

It is easy to lose the gauge calibration.