Hi! The o2 sensors will look like this please click here http://www.google.com.ph/imgres?imgurl=http://www.justparts.com/listings/photos/19772076/full/5e67e2cd-fdc8-4bdb-acf1-5774188e503a.jpg&imgrefurl=http://www.justparts.com/Auto_Parts/19772076_New-oxygen-sensor-for-2001-2006-Audi-A4-A6-S4-and-Volkswagen-Passat&usg=__pj4ooigIQ5WEPXWKY1W_Flc2ZlE=&h=307&w=393&sz=14&hl=tl&start=9&um=1&itbs=1&tbnid=T7-XIgHZYkS6AM:&tbnh=97&tbnw=124&prev=/images%3Fq%3D2002%2Bvolkswagen%2Bpassat%2Bo2%2Bsensor%26um%3D1%26hl%3Dtl%26sa%3DN%26rlz%3D1W1ADBF_en%26tbs%3Disch:1 It can be located right next to the engine at the exhaust manifold. This will not be an easy job and requires a lot of patience. You may want to raise the car and remove the panel on the wheel well to gain access to the electrical connectors. Hope this helps and have a good one!

Removal & Installation

1. Disconnect the negative battery cable and place it away from the battery's post.
2. Detach the oxygen sensor electrical wiring harness.
3. Using a oxygen sensor socket (sold at most parts warehouses) of a closed end wrench of comparable size, loosen the sensor from the exhaust.
4. Remove the oxygen sensor from the exhaust.

1. To install simply thread the sensor into the exhaust and tighten.

1. Disconnect the heated oxygen sensor harness electrical connector.
2. If installed, open the tie wrap.
3. Using a suitable tool, remove heated oxygen sensor.
4. Installation is in reverse order of removal noting the following:


Install all tie wraps in their original locations, to prevent the wiring from contacting exhaust system Apply a light coating of an anti-seizing compound to the O 2 S threads. DO NOT allow the compound to enter sensor slots Tighten to: 37ft. lbs. (50 Nm)