Sonata Gasoline power loss

I had a similar issue with my Sonata Gasoline! Does it feel like the car hesitates when you accelerate, almost like turbo lag? I would also describe the feeling like trying to breathe through a straw. Did you notice any unusual noises, maybe a slight whistle at certain RPMs? Have you checked the bypass valve or the compressor surge? Also, do you have the exact error code?

Thanks for your reply! It does hesitate, yes, just like turbo lag. I haven’t noticed any whistling, but I'll listen more closely. I haven’t checked the bypass valve or compressor surge because I’m not sure how to do that. I don't have the error code, but I will get it when I can. Is it possible that it is vacuum switching valve?

Yes, it's entirely possible it's the vacuum switching valve, especially given the symptoms. The pressure sensor could also be faulty, but based on my experience and the issues you're describing, my first guess would be a defect vacuum switching valve. Honestly, without the error code and the equipment to properly diagnose it, you're probably best off taking it to a reputable workshop. The longer you drive it like that, the more stress you're putting on other components.

Thank you for the advice! I took it to the workshop. They confirmed it was a defect in the vacuum switching valve, just as you suspected. The repair cost 140€. All the symptoms are gone, and the car drives normally again.