Peugeot Boxer Exhaust Leak

Sounds like a faulty exhaust temperature sensor. Is your Boxer's exhaust system making any unusual noises? A leak can mess with the sensor readings and cause those symptoms. Check for soot around joints in the exhaust system; it's a telltale sign.

Thanks for the quick reply! I'll definitely check for soot. If it is a leak, is it something I could patch up myself, or am I better off taking it to a shop? And would that explain the increased fuel consumption too?

Patching it might work temporarily, but it’s best to get it properly welded or replace the faulty exhaust component to ensure it seals correctly. A leak throws off the O2 sensor readings, messing with the engine management and causing it to overfuel. I would take it to a workshop.

Thanks a bunch for the advice! I took it to the shop, and you were spot on – it was a leak in the exhaust system causing the temperature sensor to go haywire. The repair cost me about 265€, but at least it's running smoothly now! I really appreciate the help!