Oxygen Sensor
NOTE:
It is important that intake air temperature be 60-95°F (15-35°C) for CO level adjustments.
- Connect an exhaust gas analyzer to test point. Warm engine to operating temperature. Disconnect oxygen sensor wire. Note CO% level.
- Disconnect and plug vacuum hose from fuel pressure regulator. The CO% level should increase. Reconnect oxygen sensor wire. The CO level should decrease to 0.6-1.0% (911 Carrera), or 0.4 0.8% (944). If not, test the DME control.