Seat Ateca Diesel Engine Issue

Sounds like a similar issue I had with my old Volvo. The check engine light and reduced power are classic symptoms. That whistling noise is probably a leak from the air intake system somewhere if I had to guess. Have you checked the sensor itself? Sometimes they just get dirty or the connection gets loose.

Yeah, I checked the sensor and the connections visually, and they seemed okay. I even tried cleaning the sensor with some contact cleaner, but no luck. The temperature gauge seems to be fluctuating a lot. You mentioned you had a similar issue with your Volvo. Was it also the charge air temperature sensor, and what was the fix?

Yep, my Volvo was throwing similar codes related to the air sensor and having engine sensor issues because the temperature gauge was out of whack. I tried cleaning it and checking connections like you did, but eventually I just gave in and brought it to a workshop. They ran some proper diagnostics and found it was a corroded wire causing intermittent readings. It's probably beyond basic DIY at this point, just get it checked at a shop.

Just wanted to close the loop. Took it to a local workshop and they confirmed it was a faulty charge air temperature sensor cable. They replaced the cable and plug connection. Cost me 95€. The check engine light is off, the power is back, and the whistling is gone. Thanks again for the help!