My car has done 37,825 miles; its check engine DTC P0170 diagnosis is that its Air Mass Meter is causing a Fuel Trim Malfunction reading.
Given its low mileage, I suspect its "hot wire" has a bit of dirt on it.
I've read that some ES300 Lexus owners in England have very very carefully cleaned the "hot wire" of their cars' meter and so save the replacement cost.
Anyone successfully done that to his M-B?
Tom