Using a lambda meter, I get a reading that is essentially stable (minimal needle movement) at '5'. This suggests that the O2 sensor is not doing its job, yet the O2 malfunction lamp does not indicate a problem.
Can someone (stevebfl ?) explain what condition and threshold triggers the malfunction lamp? Is it possible to have a failed O2 sensor without triggering the indicator?
Looking forward to your input on this one. Thanks,