Gas guage-oxygen sensor?

Disconect batery for one hour , when you fill gas stop at first click , do not overfill .

Its the fuel level sensor that is faulty.Its about $85.00 at www.rockauto.com.

IT SOUNDS LIKE YOU HAVE 2 UNRELATED PROBLEMS. THE CHECK ENGINE LIGHT 9 OT OF 10 TIMES IS DUE TO AN O2 SENSOR, ITS PART OF YOUR SMOG EQUIPMENT. IF YOU DRIVE RELATIVELY SHORT DISTANCES ALL THE TIME THE OXYGEN SENSORS WILL GET PLUGGED CAUSING THE LIGHT TO COME ON, REPLACING THE OXYGEN SENSORS ISNT A BIG DEAL. NOW FOR THE GAS GUAGE NOT WORKING, IT COULD BE A FEW THINGS, FIRST CHECK YOUR FUSES, IF THEY ARE OK, IT COULD BE A RELAY, A BAD GUAGE OR JUST A LOOSE WIRE TO THE GUAGE,OR THE SENDING UNIT FROM THE TANK TO THE GUAGE. BUT MOST LIKELY ITS PROBABLY A SENSOR THAT HAS GONE BAD.

GMC sent me a letter saying that gas guage not working has been a problem and they will fix and pay half.
Also my mechanic says that it is common to get a check engine lite when you add gas to tank, especially when you fill it. Sometimes I will take off gas cap and let air out then replace cap and the check engine lite will go off. (usually). Nothing to worry about.

Sorry ta have ta tell ya but it's a cat, best take to ya chevy dealer to take a look and they will sort it out fer ya for around $50.

The problem is probably the fuel level sensor in the fuel tank.It can be replaced separately.You don`t have to replace the fuel pump and the level sensor.Hope this helps.Good luck.

The new design filler neck on newer gm vehicles don't have a flap. The flap was just to keep stuff from falling in. I've had problems with the fuel sending unit in the tank on these vehicles.

their are several possibilities sending unit is malfunctioning or a short in the wires, if 2006 is it not still under warranty?

The sending unit in your tank is bad replace it.

yes. the fuel sending unit in the gas tank does need to be replaced