change time AUDI A4 1997 B5 / 1.G AFC Engine Oxygen Sensor Control Checking Before Converter Workshop Manual

24-47
With a properly functioning oxygen sensor, the
actual control learning values can be checked.
Various malfunctions (e.g. intake air leakage,
faulty fuel injectors etc.) can cause a change in
the mixture composition. These malfunctions are
recognized by the oxygen sensor and are
corrected via oxygen sensor control by adjusting
the fuel injection time via the ECM. Fuel injection
time that deviates from the programmed basic
fuel injection time indicates a malfunction of
some type.
These deviations are shown (oxygen sensor
control learned values) in display group 005
(bank 1) or 006 (bank 2). There is a deviation
between idle and partial load readings; the
deviation between actual fuel injection times and
the programmed basic settings are indicated as a
percentage (%).

Positive oxygen sensor control learned
values (+%):
Programmed basic fuel injection time too short
(mixture too lean), actual fuel injection time
by ...% longer , so that = 1 can be obtained.
Negative oxygen sensor control learned value
(-%):
Programmed basic fuel injection time too long
(mixture too rich) , actual fuel injection time
Pa
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