Posted by Andrew Moorey on February 27, 2007, 5:52 am
Emissions failed at4%+ CO at fast and natural idle. No output from O2 sensor which is frozen at 250mV. Aftermarket unit fitted recently prior to purchase by customer. However on checking voltages to sensor I have a battery volt relay feed to heater and batt volts on heater earth, Autodata shows this wire is a switching earth via ECU but however long the engine runs for this voltage doesnt change and is present with sensor disconnected. Also instead of the 5v reference voltage to sensor I have batt volts. Fault codes up for O2 sensor circuit which wont clear plus another relating to an intake flap. Before ripping into the job I suspect an earth fault or ECU fault but wondered if anyone has come across it before?