Twingo Oxygen Sensor Error

O2 sensor issues are common, especially on older cars. That mileage (218438 km) is getting up there. Before replacing the catalytic converter, have you tried cleaning the sensor connection with electrical contact cleaner? Do you know the exact error code? That could point to a sensor malfunction or something else.

Thanks for the fast answer! I have not cleaned the connection, but that is a very good idea and I will try it! I don't have the exact code, but it referenced the 'aged oxygen sensor'. Is it possible that a defective plug connection could trigger the error message 'aged oxygen sensor'?

An 'aged' sensor message can sometimes be triggered by a bad connection. The sensor might be fine, but if the signal isn't getting to the car's computer properly, it might throw that code. Considering the car's age and mileage, the sensor might be on its last legs. I'd recommend getting it checked out at a workshop to be sure. They can test the sensor properly and see if it's actually faulty or just a wiring issue.

Thank you so much for your help! I cleaned the plug connection, but the error message is still there. I will visit a workshop next week. They quoted me about 95€ for the oxygen sensor replacement. Hopefully, it fixes the issue, because I really like my Twingo!