Also the gauge doesn't work stays on full, could it be something eles? I think the numbers are 0460 on code. is there a fuel cluster under the dash board?
I replaced the fuel pump, now a code comes up, code says (fuel level sensor A) on 2001 Mercury Sable
The problem is probably the fuel level sending unit is faulty or became dislodged when you changed the fuel pump. Check eletrical harness as well to make sure it is still connected.