Hello,
my Car is a 2012 ML350 W166 with Engine M276 Flex Fuel.
It has Idle running problem, not speeding well and has a smell of gas.
the computer tells me that the High Pressure Fuel Pump is defect, replaced but still the same problem.
Now it seems that the Mass Air Flow Sensor needs to be replaced but I don't have it, can't find it attached to my engine where it should be.
Does my car doesn't has it? Where is the location?

Any help would be grateful.
Thank you