2001 gauge reads 1/4 when tank is empty

I changed the seal on the tank filler neck, now I run out of gas at 1/4 tank. Any idea how to "reset" the gauge?

2001 3.8 V-6 5-speed

If thats all you did it sounds like something,(part of the seal), fell in there and is sitting in the well under the float.

Very good possibility. Guess I have to drop the tank tomorrow to find out.