Skoda Praktik NOx Storage Catalyst Aging

The check engine light and error code, along with the exhaust leak, strongly suggest an issue with your NOx storage catalyst. I had a similar problem with my previous Opel Astra; NOx emissions were high, and the engine light was constantly on. Addressing the leak is paramount; a faulty exhaust system throws off the sensor readings, impacting NOx emissions and fuel efficiency.

So, you think the leak is definitely the primary suspect here? I was worried it might be the NOx storage catalyst itself failing, given the mileage. Any specific areas of the exhaust system I should be inspecting closely before taking it to a shop?

Focus on the exhaust system first. The leak allows unmetered air into the system, disrupting the combustion process and skewing sensor data, leading to the NOx emissions problem. While the catalyst itself might be aging, sealing the exhaust leak should be the initial step. If the issue persists after the leak is addressed, further diagnostics regarding the catalyst's efficiency will be needed. I would recommend a workshop assess the exhaust system.

Took the Praktik to a local shop as advised. They confirmed the exhaust leak and, after welding, reset the engine light. Total cost was 265€. Fuel efficiency already seems to be improving. Thanks for the heads-up!