How to Remove an Oxygen Sensor on a Audi A6 4.2

1. Raise the Audi using the jack and set all four corners onto jack stands so that the vehicle is solid and secure. Make sure there is enough room for you to move underneath the car, and double check the car is secure on the stands prior to crawling underneath it.
2. Locate the sensor on the exhaust. This is just behind the catalytic converter on the exhaust, and it has the only electrical connection on the exhaust. Unplug the wiring harness using your hands, and then remove the sensor using the oxygen sensor wrench.
3. Apply a thin layer of the anti-seize compound to the threads of the replacement oxygen sensor using the applicator provided with the anti-seize compound, and be very careful not to get any on the sensor head itself. Screw the replacement sensor into place.
4. Drop the car off of the jack stands using the jack.