Mass Airflow Sensor: Rio

Warm up engine to normal operating temperature and let idle. Backprobe and measure voltage between MAF sensor harness connector terminal No. 2 (Green/Yellow wire) and ground. See Figure. At idle, voltage should be 0.6-0.8 volts. When engine is accelerated, voltage should be between 3.0-4.0 volts at 3000 RPM. If voltage is not as specified, replace MAF sensor.