Seat Ateca Exhaust Flap Issue

Loud exhaust noise and an error code definitely point towards the exhaust flaps. The flaps themselves might be okay, but it's often the flap motor that fails. When you say "not working", do you mean they're stuck open, stuck closed, or not moving at all? An exhaust blockage can also cause similar symptoms, so that's another thing to consider. Do you have any way to check the actuator?

Good point about the flap motor. I should have clarified. When I say "not working", I mean the diagnostic tool shows an error related to the flap actuator circuit. I haven't physically checked the movement of the exhaust valves themselves yet. Is there an easy way to test the flap actuator without specialized tools? I suspect it's either a faulty actuator or a wiring issue to the actuator, but I'm not sure how to proceed.

Okay, if you're getting an electrical error code for the flap actuator, and the noise coincides with that, it pretty much confirms the actuator is the problem. You could try checking the wiring harness for obvious damage, but honestly, at that mileage, it's likely the actuator itself. Unless you're very comfortable with electrical diagnostics, replacing the actuator is probably the most straightforward solution. I would recommend taking it to a workshop.

Just wanted to close the loop on this. Took the Ateca to the local garage, and they confirmed the exhaust flap actuator was indeed faulty. They replaced it, and the error code is gone, the noise is gone, and the car is running perfectly. The exhaust repair ended up costing 190€, as predicted. Thanks for your help!