Fault description
Diagnosis monitors the signal voltage of the oxygen sensor before catalytic converter in overrun mode.
The fault is detected when the voltage is lower than 2.9 V in overrun mode.
Possible cause of fault:
- Visual inspection of lines and connectors (water or corrosion in connector?) Unplug connector and FIRMLY reconnect several times
- Oil or fuel in exhaust gas during overrun fuel cutout (fuel tank vent valve stuck open)
- Catalytic converter clogged (rich exhaust gas at oxygen sensor during overrun fuel cutout);
- Line defective
- Oxygen sensor before catalytic converter defective