Adam NOx Catalyst and Exhaust Leak

Interesting. I own an Adam as well, and I experienced something quite similar not too long ago. The check engine light kept coming on, and the diagnostics pointed towards emissions issues. Did you notice any changes in fuel economy or engine performance alongside the exhaust leak?

No noticeable changes in fuel economy or engine performance. The exhaust leak is a recent observation. Did your issue also involve a physical leak in the exhaust system, or was it solely an electronic error indication?

In my case, it turned out to be a small crack in the exhaust manifold. The garage identified it pretty quickly. Given that you have an exhaust leak too, it’s quite likely the root cause. I'd recommend taking it to a reputable workshop for a thorough inspection. It ended up costing me about 265€ to get it sorted. Is it worth trying to repair it yourself?

A visit to a competent workshop appears to be the most prudent course of action. The exhaust system had a leak that was causing the NOx catalyst to function improperly, which has now been resolved. Thanks again for sharing your experience.