Lexus CT200h NOx Catalyst Error

Oh no, that doesn't sound good! With the exhaust smell and the NOx catalyst error, could you have a leak somewhere in your exhaust system? I'd be worried about air quality inside the car with exhaust leaking. Are you having any performance issues?

Performance seems normal, thankfully! If it is an exhaust leak causing the NOx issue, is that something that can damage other components? I wouldn't want to make things worse by driving it.

I'm no expert, but driving with an exhaust leak can't be good, especially with that catalytic converter involved. It might be best to get it checked out by a professional to avoid further damage. Catalytic converters aren't cheap!

Thanks so much for the advice! I took it to a shop, and you were right – a small exhaust leak was the culprit, causing the NOx sensor to freak out. Repairing the leak cost me 265€ and all is well now!