DS5 Exhaust Treatment Malfunction

I had a similar problem with my DS5. Engine light came on, and it stank of exhaust fumes. Have you checked your NOx sensors? Sometimes they throw a code and mess with the catalytic converter.

Is there a straightforward way to assess the NOx sensors, or is specialized diagnostic equipment required? Could a faulty exhaust pipe also be the reason for the malfunction?

Assessing the NOx sensors usually requires diagnostic equipment to read their output. A faulty exhaust pipe could contribute, but the sensors are a common issue. Best to get it checked at a workshop to pinpoint the exact cause before replacing parts unnecessarily. Could save you some cash and time.

The workshop confirmed the lambda sensor was defective, just as I suspected. The replacement cost 375€. The issue is now resolved. Thanks for the input.