Captiva exhaust leak NOx catalyst error

Sounds familiar. I have a Captiva too. Those symptoms point to a potential exhaust leak upstream of the NOx catalyst, maybe a crack in the manifold or a bad gasket. The leak throws off the oxygen sensors, which then screws with the NOx reduction process. Think of it like trying to bake a cake with a hole in your oven – the temperature never stays right. Have you noticed any change in fuel economy or engine performance?

Interesting analogy! Fuel economy seems normal, but the exhaust smell is definitely new. Where exactly should I be looking for this leak? Any specific spots that are common failure points on the Captiva?

Without seeing it myself, I would suggest checking around the exhaust manifold first, especially where it bolts to the engine head. Also, inspect the flex pipe – it's designed to absorb vibration, but it can crack over time. Honestly, chasing exhaust leaks can be tricky, like finding a needle in a haystack. Given the NOx catalyst error, it might be worth getting it checked out by a shop. A small leak now could lead to bigger problems, possibly even damage to the catalyst itself.

Thanks, that's really helpful. I took it to my mechanic and they confirmed it was a small leak in the exhaust system right before the catalytic converter. Repair cost was 265€, so not too bad. Hopefully, that's the end of it!