Skoda Fabia mixture preparation error

The symptoms you describe certainly point to a mixture preparation problem. Reduced power, rough running, stalling, and the check engine light all suggest something is off with the air-fuel ratio. Since you suspect the injectors, that is a good place to start. Before replacing them outright, have you considered other possibilities? A faulty mass airflow sensor can also cause a rich mixture, leading to similar issues. Also, when was the last time you checked your spark plugs? Fouled plugs can definitely contribute to poor engine performance and jerking. Have you inspected the throttle body for carbon buildup? A dirty throttle body can restrict airflow and affect the air-fuel mixture. I would advise checking these components first to get a clearer picture of what's happening.

Thank you for your advice. Could a malfunctioning mass airflow sensor cause the engine to stall completely at idle, and to jerk when accelerating only sometimes? Also, where can I find the throttle body to check for carbon buildup?

Yes, a faulty mass airflow sensor can absolutely cause stalling at idle and intermittent jerking during acceleration. It is responsible for measuring the amount of air entering the engine, and if it provides incorrect data, the engine control unit will miscalculate the air-fuel ratio. This is more likely with a rich mixture. Regarding the throttle body location, it is usually situated between the air filter box and the intake manifold. It's the part that controls how much air enters the engine. You might want to consult your vehicle's repair manual for a precise location, as it varies from engine to engine. However, given the symptoms and your initial suspicion of a defective injector, I recommend visiting a workshop to perform diagnostic tests.

I appreciate the insights. The issue was indeed a defective injector. I had it replaced at a workshop; the final cost was 515€. The car is now running smoothly again. Thank you for your assistance.