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• OVERALL DIFFICULTY INDEX: 3/10
• IF YOU HAVE NO TOOLS YOU SPEND $40 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 on a cold engine. Be careful when performing this procedure on a warm engine because the lambda sensors are mounted directly on the exhaust and can reach very high temperatures.
  

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.

NOTE:
This intervention was carried out on a Peugeot 208 equipped with the PureTech engine but remains valid for all vehicles equipped with this engine or the EB2M engine including the Peugeot 301, 108, 2008, Partner and Citroën C1, C3, Berlingo, etc. Replacing the oxygen sensors on other vehicles is also almost identical.

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Symptoms of an ageing oxygen sensor

Typical average lifetime of an upstream 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
• Increased fuel consumption
• Different OBD2 codes generation in relation with O2 sensors
  
• OBDII codes P2195, P2196, P2271
  

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Location of the O2 sensors on the Peugeot 208 and preparatory works to replace them

• The oxygen sensors on the Peugeot 208, here equipped with the PureTech 1.2VTi engine, located on either side of the catalytic converter, are identical and relatively easy to access. For this reason, they will be replaced at the same time if any fault is detected on either of them.
• If your Peugeot is equipped with the EP6 engine, visit our page specific to this engine.
• The sensor upstream of the catalytic converter is located just in front of the catalytic converter (first picture).
• The downstream sensor is visible to the right of the catalytic converter (second picture) and is accessible from below, even without raising the vehicle.
• Start by disconnecting the battery.

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Dismounting and refitting oxygen sensors on the PureTech engines

Disconnect the oxygen sensor connector and free the wire harness from the clips along its entire length.
Bend the probe wire, insert the 22mm slotted socket, and apply enough force to unscrew the probe.
A sharp tug at first may loosen it, but it will unscrew very easily afterward.

The procedure is identical for the oxygen sensor located downstream of the catalyst:

Tighten the new oxygen sensor to 5 mKg.
Remember to route the O2 sensor wiring harness through the various attachment points provided.

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Detail of the tool specific to oxygen sensors

This is a 22mm slotted socket.
​This tool is specific to oxygen sensors and not to any particular vehicle.

See also our other tutorials in relation with the Peugeot 208 and PureTech engines...

PureTech engine repair manual

...and buy your universal or Peugeot 208 specific O2 sensor and tool here:

all our car repair tutorials