2003 Evo 8. Heavily modded.

So lately, every time the fuel tank gets to a quarter left in the tank when I start the car suddenly the needle will be as far down as it can go and the light will be on, even though just a minute ago before turning off and restarting the car it was right at 1/4th left. The light will stay on until I put more fuel in. I don't know if my gauge is reading wrong and Im driving with less fuel than I thought or what.

Any ideas?

 

Probably a faulty level sensor.