GLK charge air temperature sensor issue

Interesting. I have a GLK as well, and experienced something similar not too long ago. The hissing sound is a big clue. Have you checked the air intake system for any obvious leaks or cracks? The charge air temperature, or airflow sensor as some call it, plays a crucial role in the engine's performance, as it measures the temperature of the air entering the engine. Temperature fluctuation can definitely trigger these symptoms.

Thanks for the reply. When you say 'similar', are we talking about the same error code? And did you also have a whistling sound? Where exactly did you check for leaks?

Yes, I had the same error code related to the charge air temperature sensor. The whistling sound was indeed present, most noticeable during acceleration. In my case, the issue stemmed from a loose connection at the sensor itself. I'd advise a thorough inspection. However, given your symptoms, especially the reduced power, I'd recommend taking it to a workshop for a proper diagnostic. It could be a simple fix, but ignoring it could lead to more serious issues.

Appreciate the insight. Turns out, it was indeed a faulty connection, as suspected. Workshop confirmed it and replaced the plug. Total cost: 95€. All good now.