Livinia exhaust temperature sensor issue

That sounds concerning! A faulty exhaust temperature sensor can certainly cause those symptoms. Have you tried scanning the car's computer for error codes using an OBD2 scanner? Knowing the specific code would help narrow down the issue. Also, can you hear or feel any exhaust leaks? A visual inspection of the exhaust system might reveal something.

Yes, I used an OBD2 scanner, and it returned error code P0420, which points towards catalytic converter efficiency below threshold. But given the other symptoms, I still suspect the exhaust sensor is the root cause, possibly triggered by a small leak. Is it plausible that a minor exhaust leak could affect the sensor reading enough to trigger that code?

Ah, P0420 does complicate things. While it directly relates to catalytic converter efficiency, a minor exhaust leak upstream of the converter could indeed skew the exhaust sensor readings. The sensor is highly sensitive, and even a small change in exhaust gas composition can throw it off. Given the symptoms and the code, it would be prudent to have a workshop diagnose the exhaust system and sensor integrity. Replacing the sensor without addressing a potential leak might only provide a temporary fix.

Thanks for the advice. I took it to a workshop, and they confirmed a small exhaust leak near the sensor. They replaced the faulty exhaust temperature sensor and repaired the leak. The total repair cost was 265€. The car now runs smoothly, and the check engine light is off.