XC60 Exhaust Temperature Sensor Issue

Reduced engine power and higher fuel consumption could point to that sensor. Have you noticed any temperature fluctuation issues?

Good point. How would I best check for temperature fluctuation issues?

If the sensor is faulty, it's difficult to spot without proper tools. Given the symptoms and mileage, it's likely time to get it checked by a workshop.

Just got it back from the shop, it was the exhaust temperature sensor. They replaced it, and the leak was sealed. Total cost was 265€. Runs like a charm now!