I have a 2000 4Runner 4x4. I just bought this car a month ago, I replaced the fuel sending unit and re calibrated the fuel Gage. The fuel light came on and about 10 miles later it felt like it was running out of gas. I pulled into a gas station and it took 15.5 gallons. The tank is 18.5 gallons what happened to my other 3 gallons.