Thanks - that's interesting. So lean = < 0.45v Rich > 0.45v
I can't beleive it's running _that_ rich to push the voltage up as high as 5v, so that suggests a problem with the sensor.
However, let's assume that it is a "true" reading (or at least in the right direction). That suggests a (very) rich mixture in that bank. Would a rich mixture damage the cats over time?
I've only done about 1,500 miles in the last 12months. Is this relevant? And the battery went flat over winter - meaning loss of power to the ECU - so has something been "reset" somewhere that might cause this?
The hydrocarbon and CO2 readings were fine, can anything be inferred from this?
