Seat Formentor Charge Air Temperature Sensor Error

Whoa, that's a classic sign of a dodgy temperature sensor! The ECU is probably pulling back on power to protect the engine because it's getting weird readings. The whistling and hissing sounds like an air leak somewhere in the intake tract, possibly related to the sensor issue if it's messing with the air/fuel mix. Have you checked the wiring and connections to the temperature gauge sensor? Sometimes it's just a loose plug or corroded wire.

Thanks for the quick response! When you say 'intake tract', are you referring to the entire system from the air filter to the throttle body, or is there a specific area I should be focusing on? Also, what's the best way to check for corrosion on the sensor plug? I'm assuming visual inspection and maybe some electrical contact cleaner?

Yep, sounds like you're on the right track! The intake tract is everything from the air filter to the engine. But since you're getting a sensor error, focus on the area around the temperature sensor first. And yeah, visual inspection for corrosion is the first step. Look for any green or white powdery stuff on the contacts. Electrical contact cleaner is your friend. If that doesn't solve it, it might be worth getting the sensor itself tested. If you are unsure maybe take it to the workshop.

Finally got around to checking the charge air temperature sensor. As suspected, the cable connector was indeed the culprit. Replaced it, cleared the error memory, and all seems good. Parts and labor came to about 95€. Thanks for confirming my suspicions!