Lambda probe or oxygen sensor: Function and maintenance

What is it?

The lambda probe, also called the oxygen sensor or O2 sensor, first made its appearance in the 1970s, but it was not adopted in Europe until 1993, particularly for petrol vehicles. It allows compliance with the EURO 1 standard (emission standard for air-polluting gases).

The lambda probe, situated before the catalyser, permanently measures the quantity of oxygen present in exhaust gases to change the air-fuel mixture. It is possible to find a second one after the catalyser. It therefore allows checks for proper function.

How does that work?

There are two types of lambda probe:

  • The probe is heated by the exhaust gases, having an operating threshold at between 300°C and 600°C.
  • The probe heating up, in its turn, allows attainment of an operating temperature more rapidly.

Once the engine has warmed up, the probe measures the quantity of oxygen present in the exhaust gases, then sends that information to the computer, which takes charge of adapting the air-fuel mixture as optimally as possible.

What are the problems arising from a lambda probe?

The life cycle of a lambda probe is around 150,000km. However, as it ages, it sends information slower and slower to the computer, which ends up by working in a degraded state. It then enriches the air-fuel mixture, causing clogging of the probe and the catalytic converter.

What are the symptoms of a clogged lambda probe?

  • Lit engine lights
  • Over-consumption of petrol
  • Unstable idling
  • Loss of performance
  • Failure at a Roadworthiness Test

How is the lambda probe maintained?

Preserve your lambda probe for longer thanks to de-scaling by FlexFuel Energy Development® hydrogen injection. Regular engine cleaning allows, in fact, a slowing of the lambda probe’s ageing process.

Find out everything about de-scaling

Find out everything about de-scaling