02 Sensor Problems?

[S3 Chris]

Evenin All,
Have been logging block 32 on vagcom but have been getting constant values through the rev range, it just doesnt seem to change.

Readings are


-3.1% constantly on Bank 1, sensor 1, idle (Oxygen sensors learning values fuel trim at idle (Additive), )

and

-3.8% constantly on Bank 1, sensor 1, partial load (fuel trim at elevated engine speeds (Multiplicative),

Anyone had problems with their o2 sensor?
Car is running lean at top end just now, thought this might be a potential cause (Thanks DEECE for the checks doc by the way, pointed me in the right direction )

 

[HTC]

Measuring block 032 is the lambda learned values that the ECU adapts to. Correct range should be between -9 -> 9% in zone 1 and -25 -> 25% in zone 2. So you are within spec.

To check lambda voiltages look at measuring block 033. Zone 2 corresponds to lambda voltage 1.5V is Lambda 1. Log some runs and see how you get on with regards to rich or lean voltages.

 

[S3 Chris]

ah ok I think I get what you mean.

so is it to be expected that the block 32 values will be the same throughout the rev range, and that there are not different learned values for different throttle positions?

looks like its block 33 to be logged this evening. ta.

 

[HTC]

As all engines are not the same with regards to efficiency, hydrocarbons in the oil, friction, component differences etc etc, the ECU has to adapt to find its base starting point and has changed fueling to suit.
Too much deviation from a predetermined point would indicate a problem, ie vacuum leak or component failure.

With this in mind, I would not expect those values to change unless you reset the ECU, whereby it would need to re-adapt.