Volvo C30 rough running engine

The symptoms you describe, particularly the reduced power, rough running, and stalling, do suggest a mixture preparation fault. Have you considered the possibility of a defective injection valve or injector? It would also be prudent to inspect the air-fuel ratio, oxygen sensor, and intake manifold for any anomalies before proceeding.

Thanks for the reply! When you say defective injector, what exactly should I be looking for? Is there a way to test it myself without special equipment? And could a dirty catalytic converter cause similar problems?

While a partially blocked catalytic converter may contribute to performance issues, the constellation of symptoms you described initially strongly indicates an issue with the fuel injection system. Without diagnostic equipment, assessment of injector functionality is challenging. It is recommended to have the injectors assessed by a qualified technician. The diagnostic procedure will involve checking the spray pattern and fuel delivery rate of each injector. This level of assessment necessitates workshop facilities. The error code strongly suggests an injection problem.

Okay, I understand. I took your advice and brought it to a workshop. Turns out you were right! It was indeed a defective injector. The repair cost was 515€. Thanks for your help!