Lexus CT200h Exhaust Leak

I had a similar issue with my CT200h. Have you checked for any exhaust leaks? A leak upstream of the sensor can cause it to read incorrectly, triggering those symptoms. It messes with the emission control system.

Thanks! I haven't specifically checked for leaks. Is there a common spot on the exhaust component where these cars tend to develop them? Or any way to easily check it?

On mine, it was a small crack near a weld on the exhaust manifold. Difficult to spot without a thorough inspection. Given your mileage, a failing exhaust sensor is plausible, but the leak would be my primary suspect. Best to get it smoke tested at a shop.

Took it to the shop, and you were spot on! Small crack in the exhaust manifold, right where you described. Replaced the faulty exhaust sensor and fixed the leak; cost me 265€. Runs like new. Thanks for the help!