Megane diesel injector fault

Rough running and a compensation fault? Sounds like injector trouble! Has it been getting progressively worse? Any black smoke or fuel smell? Is the car down on power? Have you tried any injector cleaner? Could be worth a shot before throwing parts at it.

Thank you for your quick response. The problem did develop gradually. I have noticed a slight decrease in power, but no visible smoke or fuel odor. Regarding injector cleaner, is there a specific type or brand you would recommend for a diesel engine, and could this potentially resolve the error related to the drift compensation or is that wishful thinking?

Okay, gradual power loss seals it. While injector cleaner might help clear a minor blockage, the "reset quantity drift compensation" code strongly suggests an injector is worn or failing electronically. The ECU is trying to compensate for the injector's output being out of spec. At that mileage it is fairly common, though I would skip the cleaner and visit a workshop!

Understood. I appreciate your insights. I followed your advice and visited a local shop. After diagnosing the issue, they confirmed a faulty injector. The repair, including injector replacement and recalibration, cost 515€. The car runs much better now.