Pontiac Repair: gas guage, fuel level sensor, fuel system treatment

Question
i have a 2002 pontial bonneville and the gas guage isnt working right when i start the car it goes to full then drops to the correct tank amount showing how much gas i have but then as soon as i put the car in gear it goes to the 1/2 tank mark and stays there how can i fix this

Answer
Hi Mary:

You car needs a fuel level sensor on the fuel pump in the gas tank. This is a very common problem. The contacts arch out on the sensor from hisg sulfer content in the fuel. The pump has to be removed and that sensor replaced. It's a pretty easy fix. Make sure you get a factory gm part for it. The after market ones are worse then the original parts. While your there getting the part get a bottle of fule level/fuel system treatment to gas to the tank it has a special additive to coat the sensor so it's less apt to arch out again. Use it a couple of times a year. Good luck :)