Hi,

I have a ML230 European and 5 Emissions -Failed this year.

I already change O2 sensor, catalytic converter, spark plugs and MAF.

I spend much money replacing the components and for what?
I already send the car to mercedes and no one can tell me what the problem is

Lambda sond > Values betwen 1.06 and +/- 1.15 - MUST BE <= 1.03 Emission test failed again

I think is one thing its strange
When the throttle is on 4.000RPM and the car stoped the engine goes up and down. +/- 500RPM up and +/- 500RPM down. Its normal?

Could you help me please?
Thank you in advance