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By YOUCANIC on Nov 29, 2018

Audi Oxygen Sensor Replacement DIY Guide

In this guide, we will show you how to change the oxygen (O2) sensor on Audi vehicles. To change Audi oxygen sensor yourself, you will need a new Audi oxygen sensor and oxygen removal tool.

Typical cost to change Audi oxygen sensor yourself is less than $100. Cost to change Audi oxygen sensor at the dealer or repair shop ranges in the $200-$350. This guide will help owners of Audi models such as A1 A3 A4 A5 A6 A7 Q3 Q5 Q7 TT. 

This guide shows you how to change the oxygen sensor that is upstream of the catalytic converter. To change the oxygen sensor that is downstream of the catalytic converter you will need to jack up the or use ramps. In addition, you will have to remove the splash shield from underneath the car.

Symptoms of bad Audi O2 Sensor

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

What you will need


Open Hood

Park your Audi, set the parking brakes and open the hood. Allow the engine to cool down as well or you risk getting burned. 


Disconnect Negative Terminal

Disconnect negative battery terminal.

disconect battery before you change Audi A S Q TT models  oxygen sensor


Locate O2 Sensor

location of oxygen o2 sensor on Audi A S Q TT models  A1 A3 A4 A5 A6 A7 Q3 Q5 Q7 TT

Locate the oxygen sensor on your Audi. Above you see the oxygen sensor on an Audi Q5.

audi a4 o2 sensor location

Location of O2 sensor on Audi A4. 

Disconnect Sensor

Press the connector and pull it away to unplug the oxygen sensor.

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


Remove O2 Sensor

Place the oxygen sensor socket on the sensor and break it loose. Remove the old Audi oxygen sensor. You may need to spray penetrating oil and allow it work for at least 10 minutes. Especially on high mileage Audi cars where the O2 sensor has rusted. 

Audi A S Q TT models  oxygen sensor socket


Install new O2 sensor

Install the new oxygen sensor. Tighten your new Audi oxygen sensor to the recommended torque.

Connect the wire harness

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




Profile picture for user Vicki Swan
Rick budka, 2019-06-15

Which is the upstream vs downstream??

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