Check Oxygen Sensor
- Heat the oxygen sensors (road test car under load or run engine without load at high RPM).
- Connect Porsche System Tester 2 or scan tool and read voltage of oxygen sensor 1 after TWC.
Display: Voltage fluctuations between 0 mV and 800 mV.
Oxygen sensor is OK.
In the case of a display around 0V, give several acceleration bursts for approx. 10 seconds at 6,000 RPM. If 0V is still displayed for 1 or 2 minutes, a short circuit has occurred between the signal wire and sensor ground.
- Remove oxygen sensor connector 1 after TWC.
- Connect voltmeter to pins 3 and 4 of oxygen sensor connector towards to DME control module.
Display: approx. 450 mV
Replace oxygen sensor.
Display: approx. 0V
Check wiring harness.