Mass Airflow (MAF) Sensor
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition off. Locate MAF sensor connector. DO NOT disconnect connector. Backprobing connector, measure voltage between connector terminals No. 2 and 4. See Fig 1 . If voltage is not 0.1-0.2 volt, replace MAF sensor.