In this guide, you will find instructions on how to change the oxygen (O2) sensor on an Audi.

This guide will show you how to change the upstream oxygen sensor for the catalytic converter. That would be Bank 1 Sensor 1 or Bank 2 Sensor 1. 

In addition, to change the downstream oxygen sensor for the catalytic converter you will need to jack up the car and/or use ramps. In addition, you will have to remove the splash shield from underneath the car.


  • Check Engine Light is ON
  • A decrease in fuel economy
  • Engine Hesitation or misfiring
  • Rough Idling

What you will need


  1. Park your Audi, set the parking brakes, and open the hood. Allow the engine to cool down or you will risk getting burned. Open the hood.
  2. Disconnect the negative battery terminal. disconect battery before you change Audi A S Q TT models  oxygen sensor
  3. Locate the oxygen sensor on your Audi. Above, you'll see the upstream oxygen sensor on an Audi Q5.location of oxygen o2 sensor on Audi A S Q TT models  A1 A3 A4 A5 A6 A7 Q3 Q5 Q7 TTLocation of O2 sensor on Audi A4.

    audi a4 o2 sensor location
  4. Disconnect the O2 sensor. Press the connector and pull it away to unplug the connector. Audi A S Q TT models  disconnect oxygen sensor wire harness  applicable years: 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
  5. Remove the sensor and place the oxygen sensor socket on the sensor and break it loose. Remove the old Audi oxygen sensor.

  6. You may need to spray penetrating oil and allow it to sit for at least 10 minutes. Especially on high mileage Audi cars where the oxygen sensor is stuck.Audi A S Q TT models  oxygen sensor socket
  7. Install the new O2 sensor. Tighten your new Audi oxygen sensor to the new sensor hand tight then turn an extra 1/2-3/4 turn. 
  8. Connect the oxygen sensor wire harness by plugging it in. If you are using a universal oxygen sensor you will need to use the diagram that came with the sensor to find out which wires to splice. connect wire to finish install Audi A S Q TT models  oxygen sensor

The typical cost to change the Audi oxygen sensor yourself is around $100. 

This guide will help owners of Audi models such as the A1, A3, A4, A5, A6, A7, Q3, Q5, Q7, and TT.

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Member since 2020-09

Which is the upstream vs downstream??

Member since 2020-09

Upstream is before the catalytic converter
Downstream is after the converter