Citan check engine light and air valve issue

I also own a Citan with a gasoline engine, and I experienced similar symptoms some time ago. The check engine light illuminated, and the diagnostic pointed to an air supply issue. In my case, the engine was occasionally stalling at idle. Have you checked the vacuum hoses for any visible cracks or leaks? This can affect the manifold pressure and trigger the check engine light.

Thank you for your prompt response. When you mention checking the vacuum hoses, could you please elaborate on the specific location of these hoses and any particular signs I should be looking for, beyond visible cracks? I am not particularly well-versed in automotive mechanics, so any additional detail would be most helpful in guiding my inspection.

The vacuum hoses related to the air valve are typically located near the intake manifold. Given the potential complexity, and based on my own experience, I would recommend consulting with a qualified workshop for a thorough inspection. They can perform a smoke test to identify any leaks accurately. It's better to have it professionally diagnosed to avoid further complications.

I extend my sincere gratitude for your invaluable advice. Following your recommendation, I consulted with a reputable workshop. As you correctly surmised, the issue was indeed a defective hose connection from the pump to the air valve. The repair, including parts and labor, amounted to approximately 175€. The check engine light has been reset, and the vehicle is now functioning as expected. I appreciate your assistance in resolving this matter.