XTrail Engine Power Loss Fault Code

Reduced engine power and a stored fault code definitely suggest something's up. Have you had any aftermarket modifications done, like chip tuning? Sometimes those can cause issues, especially if they weren't properly installed or calibrated. A faulty chip tune can trigger all sorts of sensor errors and limit engine performance. Was the check engine dashboard light on?

Yes, the previous owner had some chip tuning done by a third-party provider. Is it likely that this could be the primary cause of the fault code and the reduced engine power? And what sensors might be impacted?

Given that the chip tuning was done by a third-party, it’s quite plausible that's the root of your troubles. These modifications can sometimes interfere with the engine control unit (ECU), which manages various sensors and actuators. If the tuning isn't optimized for your specific engine, it could lead to sensor readings that are out of range, triggering fault codes and limiting power as a safety measure. I'd advise taking it to a workshop to have the chip tuning checked or potentially removed.

Following your suggestion, I visited a workshop. They confirmed that the chip tuning was indeed the issue. They removed the tuning and reset the ECU. The car now runs smoothly, and the error is gone. The repair cost me 180€. Thanks for pointing me in the right direction!