my gas gauge does not work, can i get a used sensor?

The sender is in the gas tank and the tank must be dropped to replace it. If you are going to that expense, buy a new sending unit. In the meantime, calculate your MPG and zero the trip odometer when you fill up so you know how many miles have been traveled.

Used, really no used, why did the first one go bad? Get a brand new one, seeing as you're gonna have to take the mounting straps off the gas tank, drop 'er down to get to this thing...why take this trouble if you are going to have to repeat it? Will shop for you-

http://www.partstrain.com/ShopByDepartment/Fuel_Sending_Unit/PONTIAC/SUNFIRE

It's a nine year old car - might as well install a new fuel pump with that new sending unit.

For my 02 sunfire ..the fuel pump and the sendi g unit are one piece inside the tank..springloaded..if you are letting it run on empty alot condensation builds and spring sticks causing it ..welk to not work. Easy fix ..turn off radio .put in key and turn..you should hear a "whirrrring"sound..thats the pump turning on send fuel up the line ..now if u hear nothing..get a rubber mallet and crawl under locate the center of tanks bottom and give it a few good hard whacks ..it will free the spring and it should now start..worked for me on several cars.