Air Flow Meter/Sensor: Description and Operation

MAF Sensor
The MAF sensor is located in the air intake system between the air filter and the EGR valve out-take port. The ECM monitors the Mass Air Flow (MAF) sensor signal to calculate the actual amount of EGR flow into the intake manifold. When the EGR valve is opened, the MAF rate will decrease. When the EGR valve vacuum control solenoid is operated at 50-70 percent duty cycle, the MAF rate should drop at least 4 g/s.