My Mercedes C180 2002 has the engine light on.
I have got a code of 0138 and it says O2 sensor high voltage.
Does it need to be replace or could I clean it? Mileage is about 80,000 and which sensor should I change (is there only one) my code reader says bank 1
Thanks for any help
I would not be so quick to do anything. You need a shop with a scanner to monitor the sensor to verify the voltages and if they are off, to determine why. It is the upstream sensor but it could be a variety of things causing it.
Cleaning an o2 does nothing. They are not serviceable.