Skoda Octavia Hybrid NOx Sensor Problem

Check engine light and exhaust leak with a NOx sensor error... Sounds like a potential wiring issue. Have you inspected the sensor's cable and plug for damage or corrosion? A faulty connection can trigger those symptoms. Any recent work done on the exhaust system?

I had a quick look, but couldn't see anything obvious. Where exactly should I be focusing my attention on the cable and plug? Is there a common failure point I should be aware of?

Given the symptoms and error code, a faulty connection is likely. Closely inspect the plug connecting to the NOx sensor for bent pins, corrosion, or loose wires. Also, trace the cable back as far as you can, checking for any chafing or damage where it might rub against the chassis or other components. If you are not comfortable doing it yourself, I would recommend you go to the workshop.

The NOx sensor issue is resolved. It was a faulty plug, and it cost 95€ to fix. Thanks for the pointer!