How to replace the oxygen (O2) sensor on any car ​

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  • OVERALL DIFFICULTY INDEX: 3/10
  • IF YOU HAVE NO TOOLS, YOU PAY $45 TO GET THEM FOR THIS JOB
  • IF YOU HAVE NO EXPERIENCE YOU SPEND 1.5 HOURS TO CARRY OUT THIS JOB
  • RISK OF BURNS, SEE BELOW​​

BEFORE YOU START
  • Work only on a cold engine for this intervention. Do not attempt to work on a hot engine as this concerns the exhaust system with temperatures reaching hundreds of degrees.
  • Replacing the O2 sensor on other engines is identical
  • This pictorial applies to the upstream sensor (sensor 1 bank 1) but the same is valid for the downstream sensor.
​DISCLAIMER:
Our pictorials are of informative nature and do illustrate works carried out by ourselves at our own premises for our own use and satisfaction.
Readers who envisage to carry out similar works inspired by the below method shall do this at their own risks and liability.
The below works concerned a Peugeot 5008 equipped with a turbo-charged PSA BMW EP6 engine.
Same or similar engine and turbos can be found on Peugeot 207, 208, 308, 508, 3008, 5008 and Citroen C4, C4 Sedan, DS3, DS4, DS5 also the Mini Cooper S. The works remain similar or identical on any oxygen sensor of any car.

Symptoms of an ageing oxygen sensor

Typical average lifetime of an O2 sensor is 80,000-120,000 Km
This is an average, below symptoms can happen earlier:
  • Difficult engine start when cold
  • Long cranking time
  • Rough idle at all times
  • Hesitation when accelerating from idle
  • Slight loss of power
  • Increase in fuel consumption

Air fuel (A/F) or oxygen (O2) sensor removal pictorial

1- Disconnect the battery.
2- Locate the O2 sensor connector by following its wires. Disconnect it.​
3- Remove the sensor cable from its clips all along its way to the oxygen sensor.
4- A specific 22mm socket with side cut out exists (see below). You can use a spanner instead. Hold it in one hand and give it a firm hit with the other hand. It will then unscrew very easily.
5- Remove the sensor and fit the new one.
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6- The problem with the spanner is that you don't know to which torque your are forcing. If the spanner is not bigger than usual, then go ahead and tighten to the max with your bare hands.
7- Re-route the cable carefully and meticulously and fix it at every clip. Reconnect the connector.
8- Reconnect the battery and wait 5 minutes before starting the engine. 
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Buy your upstream lambda sensor from our partners' stores (See further below for France and EU):

Tool for air fuel (A/F) and oxygen (O2) sensor removal and refitting:

The specific O2 sensor 22 socket:
  • The side cut is for the sensor cable. 
  • Use it like for any bolt.
  • Tighten to 5 mKg
  • This tool is specific to O2 sensors, not the the EP6 engine

See also...