Quest exhaust back pressure sensor issue

I had a similar issue with my Nissan Quest. The symptoms sound very familiar. Have you checked for any obvious leaks in the exhaust system before the sensor? Sometimes, a small crack can cause erratic readings and trigger the warning light. What's the mileage on your car?

The mileage is at 33328 km. I haven't noticed any leaks, but I'll check again more thoroughly. If there aren't any leaks, is replacing the exhaust back pressure sensor the likely next step?

Given the symptoms and the error code, along with the low mileage, replacing the exhaust back pressure sensor is likely the solution. I'd still suggest going to a qualified workshop for a precise diagnosis and repair, especially considering the smoke. A faulty sensor can affect emissions and potentially other components. In my case the workshop confirmed the defective sensor.

Thank you for the advice. I had the sensor replaced at a workshop. The final bill came to 245€. The warning light is now off, and the smoke is gone.