Well I replaced the MAS last night on the ML, the CEL stayed on.
Was advised to drive it for a few days and after about 40 cycles of the ignition switch it should go out.
Or
Goto Auto Zone and have them reset it.
So I visited AutoZone and they scoped it with their OBD II.
Read 4 codes MAS, left and right fuel trim and air temperature sensor malfunction.

They tried 3 times to reset the codes but their reader kept coming back with all 4 codes present.

So I thanked them and drove away.

The CEL was OUT !!! Wonderfull !!!

I'm guessing the ML had to be turned off (the ignition switch) and restarted in order to finalize the resetting sequence.

The engine was NOT running while connected to the OBD II reader.

Anyone have that experience?

Thanks