Mercedes R Klasse Oxygen Sensor Issue

I had something similar with my R Klasse, though I don't remember the mileage. Automotive sensor issues can be tough. Did you check the air-fuel ratio? A bad O2 sensor will affect fuel efficiency.

Thanks. How did you figure out the cause, and what was the exact problem with your car? I want to understand the repair.

For me, the check engine light and codes pointed to the O2 sensor, but it was a corroded connector. Check the simple things first before replacing the sensor. If electrical work isn't your thing, a workshop is a good idea.

Thanks for the help. It was a bad plug connection, and the repair was 95€. The error is gone, and fuel consumption is normal again.