Ok, I recently traded in my 05 GTO for my 08 cobalt ss/tc. I really love the car and can't wait to get some mods. The car is perfect except for the fuel gauge. I filled the car last night and drove a good 25 miles, shut the car off and when I started it again the gauge read 3/4 tank. I knows thats BS because I was babying the car those 25 miles. After driving it a few miles it raised back to a little over 7/8th's. I'm assuming I have a bad fuel level sensor. What do you guys think and if so do I simply have to remove the seats and pull the sending unit or drop the tank?

 

I have the SS/TC gauge cluster in my car and it does the same thing. I think it is probably just not the greatest fuel gauge ever used. Probably not worth the hassle of changing the sensor unless it quits working completely

 

You have to drop the tank, but honestly, GM hasn't been able to build an accurate fuel gauge system since... well... ever. Just deal with it, it's accurate enough to keep you from running out of gas.