Starting in 2011, the fuel gauge is erratic-going from full to half to empty & back while driving. While idling at anytime, the gauge goes to empty & computer shows low fuel. At any of the incidents mentioned, I have gas in the tank. When the gauge on all my cars is at quarter tank, I always refuel asap. For the Malibu, it only takes 5 gallons & the gauge goes from quarter tank to full. It should be between 10 & 12 gallons.Last November, I contacted Chevrolet Division of GM for assistance with fixing the obviously factory defect. I told them the problem is the gas float or sometimes called fuel float or even fuel sensor or fuel level sensor or fuel sending unit (take your pick). But they won't believe me & asked me to get a diagnostic test. I told them it's $125.00 & I can't pay for it. They said they will assist me with it & the repair after I get the test done. Just send the dealer's test results & receipt to them. BUT when the test showed it's the gas float which is what I told them in the first place, they turned their backs & said they can't help pay for the repairs because the warranty expired long time ago. They knew the car is not under warranty anymore that's why I contacted them for assistance in paying for the repairs. They led me to believe they will help. This being my first Chevy car & it will be my last Chevy car, or last American car for that matter. I should have listen to my wife & bought foreign. I have no major problem with my other three Japanese cars. I only change the tires, brakes, oil, belts, etc (basic maintenance).

This is ridiculous of Chevy or GM, you think they would have gotten this part right out of all parts, funny thing is my ex-girlfriend had the same problem with her 2000 impala I replaced it with a 3rd part sending unit works way better, I have a 95 ford escort had it for 13yrs without fuel gauge or fuel pump issue and it has 180,000 miles and it still function great and I take good cars of my cars even very picky about the gas I put in.

Update from Nov 6, 2011: I had to drop the tank to fix this issue there is no easy access door to the fuel pump assembly you have to grow some balls and just drop the tank expect at least 4- 5hrs to complete what had happened, one of the connecting pins on the sensor broke and the sending unit give out improper voltage reading to the computer to gauge for gas leveling.

its really time consuming to drop a tank and instead of two straps GM used a one whole piece bracket but treat it like a two piece bracket you don't have to worry about the muffler being in the way (even tho it looks like its in the way but its really not) but make sure to remove or have little to or at least 2 gall of gas in the tank (that's because of weight) the lighter the easier it will be to remove the tank by moving it left to right repeatably and it will slide off the muffler with a little work but it not hard as it seems ( I did it with out all my tools) but make sure you disconnect all the hose and electrical connecter and disconnect the canisters once you worked the tank loose, and partial down you see what I mean when you start the work just take your time and observe your connection and you'll be OK installing is the reverse but still take your time reinstalling.

a side note jack stands are very helpful I used 4 of them.