Evalia rough running mixture error

A mixture preparation error in your Nissan Evalia can indeed cause those symptoms. Reduced engine power, rough running, jerking, stalling, and the check engine light are all consistent with an air-fuel ratio issue. The mass airflow sensor is a possibility, as it provides crucial data for calculating the correct fuel injection. However, you should also consider the injection valves themselves. A defective injector can cause a lean or rich mixture, leading to similar problems.

Thanks for the quick reply. So, you reckon it could be the injectors? Is there any way to test them without pulling them all out? I'm trying to avoid a huge job if I can. Is there a way to check the spray pattern or something similar? If it's not the injectors or the mass airflow sensor, what else could cause a mixture preparation error? I’m trying to see if I can diagnose it myself.

While a full diagnostic requires specialized equipment, uneven engine performance might indicate an injector issue. Given the symptoms and mileage of your Nissan Evalia, a visit to a workshop for a comprehensive fuel system check is advisable. They can perform tests to determine if the injectors are functioning correctly and identify other potential causes of the mixture preparation error.

Appreciate the advice. Took it to the shop, and you were spot on – turns out one of the injectors was faulty. Replaced it, and the Evalia is running smoothly again. Cost me 515€ all in. Thanks again for pointing me in the right direction!