Hello Everyone,

I have been trying to pass the inspection and when they do emissions test, Catalyst and O2 sensors become inoperative. They said that the O2 sensors do not write any logs into the ecu.

I had OE Tuning ecu tune so I went to the MB Dealer and flashed the ECU thinking this would solve the problem. However, it didn't. MB Dealer checked the O2 sensors and said they could not find anything wrong. They said that the problem has to do something with the ecu tune that I had, that the ecu does not see O2 sensors.

Any ideas of what would be the issue and how to fix it?

Thanks,
Andrey

 

anyone?

 

bump

 

Did ur dealer say anything abt the aftermarket tune? who said that the O2 sensors donot lof data in the ECU?

 

Front and rear O2 sensors inoperative or just rears? Some tunes have the rear O2s turned off and it would fail an OBDII emissions test. But, you said you have the stock tune so I am going to have to assume that all O2s are turned on.

 

Nah, delaer didn't say anything about the tune, my warranty is done anyways. Dealer did the test on the car and said that O2 sensors are fine it's just something that the tune did.

I believe only 2 are inoperative. OE Tuning said that they might had installed the wrong tune for my car, the one that goes for c63 with no cats. But in my understanding this would be gone after ecu flash, right? Or maybe they didn't flash it correctly?

 

Your sensors are prob turned off u need then turned back on to pass

 

Hmm, ok. Do you know if this is done through diagnostic computer?

 

I Belive it done thru tuning.