The oxygen sensor in your Buick Regal can fail. It must be replaced right away in order for you vehicle to run properly. The oxygen sensor helps regulate the oxygen and fuel ratio. It senses when more or less oxygen needs to be added to the fuel as it moves through the lines. This controls your gas mileage in your Buick. It's a bit challenging to replace the sensor yourself but can save you money.
Locate the oxygen sensor on the precatalytic converter. This will be located near the front-right wheel well of your Regal.
Unhook the large air-intake pipe that is connected to the air box and rear turbo. Also remove the two smaller air pipes that run from the air box to the blowoff. Now locate the oxygen sensor. You will need to soak it in WD-40 in order to loosen it.
Use the 7/8-inch wrench to remove the old oxygen sensor. Locate the stock sensor wire near the engine lift loop. Splice the stock sensor wire and connect it to the new oxygen sensor, using crimp connectors. Apply some of the anti-seize paste onto the threads of the new sensor, being careful not to get it on the sensor itself. This makes it easy to remove next time.
Screw on the new sensor as tight as you can by hand. Then use the wrench to fully tighten it. Snap the connector wires back into the wire holders. Reattach the air pipes again.
