Audi Oxygen Sensor Replacement DIY Guide
Last Updated on Tuesday Mar 13, 2018
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
Step 1: 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.
Step 2: Disconnect Negative Terminal
Disconnect negative battery terminal.
Step 3: Locate O2 Sensor
Locate the oxygen sensor on your Audi. Above you see the oxygen sensor on an Audi Q5.
Location of O2 sensor on Audi A4.
Step 4: Disconnect Sensor
Press the connector and pull it away to unplug the oxygen sensor.
Step 5: 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.
Step 6: Install new O2 sensor
Install the new oxygen sensor. Tighten your new Audi oxygen sensor to the recommended torque.
Step 7: 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.
Oxygen Sensor Fault Codes
If your check engine light is on due to oxygen sensor fault, the oxygen sensor itself may not always be the problem. You may have other problems such as bad wiring harness for example. You can read these codes yourself using an OBD-II code reader and clear them once you complete the repair.
- P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
- P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
- P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
- P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
- P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
- P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
- P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
- P0137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
- P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
- P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
- P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
- P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
* There may be other codes that point to a bad Oxygen Sensor.
Oxygen Sensor Torque
- 45 ~ 49 N.m (30 ~ 35 lb-ft)
These are typical values and may vary between models. Verify torque specifications by calling your dealer.
Oxygen Sensor Specifications
HO2S [Bank 1/Sensor 1]
|Heater Resistance||2.5 ~ 4.0 [20 C]|
HO2S [Bank 1/Sensor 2]
|A/F Ratio||Output Voltage(V)|
|Heater Resistance||3.3 ~ 4.1 ohm at 20 C|
Oxygen Sensor Location
Location of oxygen sensor (4-cylinder) cars
Four-cylinder engines have only one catalytic converter (Bank 1).
- Sensor Bank 1 Sensor 1 is located upstream, before the catalytic converter.
- Sensor Bank 1 Sensor 2 is located downstream, after the catalytic converter.
Location of oxygen sensor (V6) cars, SUV, VANs
V6 engines have two catalytic converters.The catalytic converter on the passenger side is often called Bank 1. The catalytic converter on the driver side is Bank 2. Upstream sensors are called sensor 1, downstream sensor are sensor 2. Verify bank locations by calling your dealer.