P0133

SYMPTOM
P0133-02 SENSOR 1/1 SLOW RESPONSE

WHEN MONITORED
Vehicle is started and driven between 20 and 55 MPH with the Throttle open for a minimum of 120 seconds. Coolant greater than 70 °C (158 °F). Catalytic Converter Temp greater than 600 °C (1112 °F) and EVAP Purge is active.

SET CONDITION
The oxygen sensor signal voltage switches less than 16 times from lean to rich within 20 seconds during monitoring. Two Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- EXHAUST LEAK
- (K41) 02 1/1 SIGNAL CIRCUIT
- (K902) 02 RETURN UPSTREAM CIRCUIT
- 02 SENSOR

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Scan Tool Testing and Procedures

DIAGNOSTIC TEST
1. ACTIVE DTC





Note: Check for contaminants that may have damaged the 02 Sensor: contaminated fuel, unapproved silicone, oil and coolant. Ignition on, engine not running.

Note: After the repairs have been made, verify proper 02 Sensor operation. If all the 02 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining 02 Sensors.

With a scan tool, read DTCs.
Is the DTC active at this time?
Yes>> Go To 2
No>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5. Powertrain Verification Test - Ver 5

2. EXHAUST LEAK

Start the engine.
Inspect the exhaust system for leaks between the engine and the 02 Sensors.
Are there any exhaust leaks?
Yes>> Repair or replace the leaking exhaust parts as necessary. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 3

3. (K41) 02 1/1 SIGNAL CIRCUIT





Turn the ignition off
Disconnect the 1/1 02 Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (K41) 02 1/1 Signal circuit in the 02 Sensor harness connector.
Is the voltage approximately 5.0 volts?
Yes>> Go To 4
No>> Check the (K41) 02 1/1 Signal circuit for a short to ground, open, or short to voltage. If OK, replace and pro gram the Powertrain Control Module per Service Information. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.

4. (K902) 02 RETURN UPSTREAM CIRCUIT





Measure the voltage on the (K902) 02 Return Upstream circuit in the 02 Sensor harness connector.
Is the voltage at 2.5 volts?
Yes>> Check the (K902) 02 Return Upstream circuit for a short to ground, open, or short to voltage. If OK, replace and program the Powertrain Control Module per Service Information. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 5

5. 02 SENSOR

If there are no possible causes remaining, view repair.
Repair
Replace the 02 Sensor. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.