1995 AUDI A4 catalytic converter

24-107


Oxygen sensor heating, Oxygen Sensor
(O2S) Heater 1 -Z29- after catalytic
converter, checking

Special Tools and Equipment

VAG1526A
VAG1594A
VAG1598/31
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11/22/2002 htt
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24-108

Test requirements:

Coolant Temperature at least 80 C.

Fuse for oxygen sensor heating OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations

Test sequence

Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access the harness connector. The coolant
hoses can remain connected. - Disconnect 4-pin harness connector -1- (brown) to Oxygen Sensor
(O2S) behind Three Way Catalytic Converter (TWC) -G130-.

If specified value is not obtained: - Connect multimeter between terminal 1 and 2 for resistance
measurement.

Specified value at room temperature: 6.4 to 47.5
Pa
ge 40 of 46 Ox
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en sensor control, checkin
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.FU07.24.2

- Replace Oxygen Sensor (O2S) behind Three Way Catalytic Converter
(TWC) -G130-.
Pa
ge 41 of 46 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.FU07.24.2

24-112

Oxygen sensor, removing and installing


Special tools and equipment

Procedure
3337 wrench, 7-piece set Locking compound G 052 112 A3

Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access harness connectors. The coolant hoses
can remain connected. - Disconnect oxygen sensor harness connector and lay to side.
1 - (brown) for Oxygen Sensor (O2S) behind Three Way Catalytic
Converter (TWC) -G130-
2 - (black) for Heated Oxygen Sensor (HO2S) -G39- before catalytic
converter
- Unscrew oxygen sensor using special tool 3337.
Pa
ge 45 of 46 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU07.24.2