Originally Posted by Greenbon
does bad O2 sensor the reason for poor on gas?
Also, how do you change the O2 sensor?
The O2 could very well be the source of your poor fuel mileage. Especially if it has not been changed in quite awhile. Your vehicle might be a little different than mine but the O2 is usually located right behine the rear exhaust manifold on the exhaust pipe. There is this special tool for removing/installing the O2 Sensor so that you don't damage the wire when your installing the new sensor. It usually has a coating of anti-seize on the new sensor'* threads. Most people here recommend you stick with AC-Delco when you buy the replacement O2 Sensor