If your Porsche 968 Air Flow Meter keeps failing the issue is most likely to much oil on a Porsche performance air filter, or to much blow by from the 968 engine.
The Porsche 968 Oxygen sensor is a critical part of the emmision control system and should be replaced as soon as it fails. Make sure to check the Porsche 968 diagnosics codes for proper replacement of the O2 Sensor.