Today I unintendedly noticed an advertisement on eBay:

In the advertisement it is mentioned that the current product is:
a. OEM sensor;
b. emulator.
I will oppose it – it is not possible to be both at the same time! OEM sensor is not an emulator, but the emulator works completely differently than the OEM sensor.
When reading the description, it becomes clear that it’s about an OEM sensor, not an emulator.
More in detail regarding differences between the emulator and the sensor you can read here (here), but the short version – if your car does not have a new (or recently installed) NOx catalytic converter, installing the OEM sensor will not give any positive result. Yes, the error messages regarding its performance will disappear, but the engine will not restore the Stratified charge, will not measure the injectors – DME will run in the limp mode: the same as it was till now. Unfortunately, the newest E series vehicles, which are equipped with N43/N53 series engines, are at least 10 years old now – in 99% of cases, their NOx catalytic converters are aged.
Remember – after replacement it is essential to perform necessary service procedures:
a. clean the NOx catalytic converter, performing desulfation session (important, if the OEM sensor is installed);
b. perform the re-adaptation of the engine (important both for OEM sensor or emulator).
Only after these service procedures, DME will restore the Stratified charge and renew injectors measurements. Of course, if there will be error messages regarding the performance of the NOx catalytic converter (30E9) or its real performance will be unsatisfactory (DME will identify it directly after desulfation session); the error messages regarding CO catalytic converters or any other system, DME will not restore the Stratified charge and this investment will be completely useless.
After installing the sensor, make sure that the DME really restores the Stratified charge! This is the only criterion, which can identify if the repair was successful.
Finally – of course, I was interested in the positive feedback:

As you see, in 3 of 4 feedbacks is marked: the error messages, which refer to the NOx sensor, disappeared. Unfortunately, none of the feedback is mentioned the most important thing – did the engine restored Stratified charge. I am skeptical.