Some cars can run without the airflow meter (though not properly), others cannot run at all.
31manifold and/or airflow meter sensor signal circuit--airflow meter/circuit--manifold pressure sensor/circuit--ecu
It does not have one.
in the car
check the airflow meter
The airflow meter is located on the air intake duct on the right hand side front of the 325i. 1) Remove the air cleaner assembly from the airflow meter. 2) Disconnect the electrical connector from the airflow meter. 3) Remove the nuts and lift the airflow meter from the engine compartment. I can explain how to perform checks to see if this is working before you change it if you wish. Please note the idle stabiliser valve and the throttle position switch can cause similar problems.
check airflow meter
if the car is running rough whilst idleing or running, simply unplg the airflow meter and test drive the car. if the airflow meter is buggered- whilst it is unplugged it should run fine
orifice meter is used for measuring volume flow rate air.
Most cars will not operate without their airflow meters. For example, Holden Commodore (Alloytech engine) You remove the connector to the airflow meter when car is running, engine shutsdown and will produce extensive error codes.
It's located under the air filter. Remove air filter and 4 screws under it and mass airflow sensor is there
Disconnect the negative battery cable.Loosen the hose band and remove the intake hose.Remove the airflow meter attaching bolts and detach the wire harness connector.Remove the airflow meter from the air cleaner housing.Installation is the reverse order of the removal procedure.