Been reading my Bentley and the readings don't make sense. If my duty cycle is high the lambda sond is making the mixture rich. But a reading of .4 on the oxygen sensor is lean? I think I have more than one problem. I am thinking the temp sensor is bad and grounding terminal 7. But is the O2 sensor fried too? The bentley just says to replace if you get no voltage, but to their readings go off as they age. My sensor is of unknown age, but it looks old. Not looking forward to getting that sucker off the manifold. Does this make sense to anyone or am I barking up the wrong tree? Its not that I was not planning to replace the O2 sensor, but I just want to diagose the problem before I go buying new parts.