ML320, O2 Sensor Replacement, Engine Code

Question by eho48 posted 7 months 3 weeks ago in M-Class

Hi,

I have a Mercedes ML 320, 2000.

I just replaced all four oxygen sensors but the "Check Engine" has returned right after the replacement.

The codes that have been indicated: 157, 161, 135, 155, 141 and 134.

Do you know why those codes would appear even with all brand new Bosch oxygen sensors?

I am so puzzled...

Thanks,

Emily