EGT sensor reconnection

The consumer’s issue:

On 12th March, the dealership changed my car’s cambelt and tyre valve, and also conducted an MOT test. The work required the business to disconnect the exhaust gas temperature (EGT) sensor in order to access the cambelt. I don’t believe they reconnected the EGT sensor after the work, and they failed the car’s MOT because of the offside front and rear shock absorbers. However, on 14th March, the car passed its MOT, which was conducted by a third party.

A week later on 21st March, a DPF warning light appeared on the dashboard, and on the 29th March, I took the car back to the dealership and told them about it light. The business attempted a forced regeneration, but it failed, so they recommended a replacement DPF. After further investigation by a third party, they discovered that the DPF side of the EGT sensor was disconnected, so they reconnected the sensor and the DPF now works as it should. I believe the dealership is responsible for the sensor being disconnected because they were the last to touch it, and should cover the costs of the repairs which I have incurred.”

The accredited business’ response:

  • The car was brought to us for an MOT, plus a tyre valve and cambelt change.
  • As part of the MOT, the exhaust emissions are tested and the engine bay is inspected.
  • Therefore, a hole in the exhaust system, due to a disconnected sensor, would have been picked up during the MOT.
  • Regarding the DPF warning light, the consumer requested that we conduct a forced regeneration of the DPF.
  • We offered to diagnose the reason for the warning light before conducting a forced regeneration, but the customer declined this offer.
  • After the forced regeneration failed, and with the customer refusing the diagnostics, we recommended that the customer replaced the DPF.
  • We were later contacted by the consumer claiming that we had failed to reconnect a sensor, leaving a hole in the exhaust system and our business liable for the repair costs.
  • However, after investigating the complaint, we do not believe that we failed to reconnect the sensor. As a result, we should not be made liable for covering for the customer’s expenses.

The adjudication outcome:

  • A disconnected EGT sensor would have meant that there was a hole in the exhaust system, and this would have allowed exhaust fumes to be blown into the engine bay.
  • As such, it is something which would have been identified by the garage during the MOT, or at least by the third party which conducted an MOT two days later.
  • The failure to notice exhaust fumes in the engine bay during both MOT tests shows that it is unlikely that the business failed to reconnect the sensor.
  • Finally, based on the information that the dealership had, and with the customer declining to consent to further investigation, the recommendation for a replacement DPF was reasonable. Therefore, the customer’s case was not upheld in their favour.


  • The customer and accredited business did not appeal the decision, and the case was closed.