Peugeot 1007 exhaust leak sensor issue

Yeah, had similar symptoms on my 1007. Check engine light, power loss, fuel economy went to pot. Have you checked for exhaust leaks? That can throw off the sensor readings.

Where exactly should I be looking for leaks? I've visually inspected the exhaust but didn't spot anything obvious. Any specific areas prone to failure?

Hard to say without a proper inspection. The welds and flanges are common spots, but a hairline crack can be anywhere. I'd suggest getting it smoke tested at a workshop. Probably the sensor is bad anyway, but the leak triggered it.

Thanks for the advice. Took it to a garage, smoke test confirmed a small leak, replaced the exhaust temp sensor while they were at it. Cost me 265€, but the car runs fine now. Appreciate the help!