How to Replace a VW O2 Sensor
- 1). Remove the O2 sensor clip from the engine wiring harness by unsnapping the clip.
- 2). Remove the exhaust manifold heat shield by unbolting the three bolts that hold the manifold shield. Place the shield and bolts to the side of your work area.
- 3). Remove the two bolts that hold the O2 sensor to the exhaust manifold.
- 4). Remove the old O2 sensor gasket on the exhaust manifold.
- 5). Lightly clean the O2 mounting surface with the wire brush.
- 6). Place the new O2 gasket on the surface of the exhaust manifold.
- 7). Install the new O2 sensor. Reinstall the exhaust manifold shield and clip the O2 sensor into the engine wiring harness.
Source...