Fortuner NOx catalyst error and exhaust leak

I had a similar issue with my Fortuner. The NOx catalyst error and exhaust leak could definitely be related. A leak in the exhaust system can affect the catalyst's efficiency and trigger that error. Is the leak before or after the catalytic converter?

Thanks for the quick reply! I'm not entirely sure where the leak is exactly. Is there an easy way to check without taking everything apart? And if it is the leak, what did you do to fix it?

Without proper tools, it's tricky to pinpoint the leak's location. Since you're getting NOx emissions errors, a leak is very bad for the environment. If you're not experienced in car repair, I recommend taking it to a workshop to get it checked out properly. They can smoke test the exhaust system.

Thanks for the advice. I took it to a workshop, and you were right - a small crack in the exhaust manifold was causing the problem. They welded it, cleared the error codes, and now it's running fine. Total cost was 265€, so not too bad. Hopefully, this solves the issue for good!