MIL ON, DTC P130 through P0160 (Oxygen Sensor) Set
Group2
Number
9603
Model
6 Cyl.
Part Identifier
2469
June 11, 1996
Subject:
Oxygen Sensor Connections
ATTENTION:
Service Manager / Service Technician
Models Affected:
911 Carrera (993) and 911 Turbo (993)
Model Year 1995 on-
Concern:
Malfunction of the oxygen sensor system and/or incorrect failure modes in the control unit memory, results in the MIL light coming on.
General Information:
The conditions mentioned above can occur if the connector in the engine compartment for the oxygen sensor is cleaned or treated with contact cleaners or other sprays, oil, grease, water etc.
The reference air for the oxygen sensor is pulled through the cable harness and the electrical connector. Cleaners or sprays will cause contamination of the reference air and/or limit the amount of reference air that reaches the oxygen sensor. This will create faults in the oxygen sensor system and may ruin the oxygen sensor.
It is therefore extremely important that the oxygen sensor connector be installed clean and dry. Contact cleaners, sprays, oils or any other liquids must be kept away from the oxygen sensor connections.
Important:
Before attempting diagnosis of the oxygen sensor's performance, disconnect the affected sensor and test drive the vehicle to operating temperature with an engine RPM of 3500 to 4000 for approximately 10 minutes. This should burn off any sensor contamination which may have occurred, and yield better test results.
Possible stored failure modes in OBD II cars (Model year 1996 911 Carrera and 911 Turbo) are P0130 (Oxygen sensor ahead of catalyst) through P0160 (Oxygen sensor behind catalyst) with the MIL light on.
Possible stored failure modes for OBD I cars (Prior to model year 1996) are:
Oxygen Sensor: Signal Unplausible
Oxygen Sensor: Open Circuit
Literature:
Refer to the 911 Turbo On-Board Diagnostic Troubleshooting (OBD II) Handbook, the 993 Workshop Manual, Vol. VIII (OBD I), or the 911 Carrera On-Board Diagnostic Troubleshooting (OBD II) Handbook.