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DTC P0133: O2 Sensor 1/1 Slow Response

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.
NOTE: The 1/1 O2 sensor is referred to as upstream oxygen sensor in this test. Upstream oxygen sensor operation is monitored with engine temperature greater than 147°F (64°C), after reaching vehicle speed of 10 MPH, throttle is off idle for 2 minutes, vehicle is brought to stop and allowed to idle with transaxle in Drive (A/T) or Neutral (M/T). DTC may be stored in Powertrain Control Module (PCM) if upstream oxygen sensor signal voltage is switching from less than .35 volt to more than .53 volt and back fewer times than required. Possible causes are: exhaust leak, slow responding upstream oxygen sensor, defective oxygen sensor heater, or defective connectors or wiring.
  1. Turn ignition on with engine off. Using scan tool, read Diagnostic Trouble Codes (DTCs). If global good trip counter is displayed and equal to zero, go to next step. If global good trip counter is not displayed or displayed with a value, go to step  5.
  2. Start engine. Check for exhaust leaks between engine and catalytic converter. If no exhaust leaks exist, go to next step. If exhaust leaks exist, repair exhaust system as necessary. Perform TEST VER-5A .
  3. Turn ignition off. Using voltmeter, check voltage drop on upstream oxygen sensor ground circuit by backprobing Black/Orange wire between upstream oxygen sensor connector terminal No. 3 and PCM connector terminal No. 27. PCM is located in engine compartment, between air cleaner and radiator. Upstream oxygen sensor is located on the exhaust manifold. Start engine and allow to idle reaching normal operating temperature. If voltage drop is less than .1 volt, go to next step. If voltage drop is .1 volt or more, repair poor connection causing high resistance on the upstream oxygen sensor ground circuit (Black/Orange wire) between upstream oxygen sensor and PCM. Perform TEST VER-5A .
  4. Turn ignition off. Using voltmeter, check voltage on upstream oxygen sensor signal circuit by backprobing Black/Dark Green wire between upstream oxygen sensor connector terminal No. 4 and PCM connector terminal No. 30. Start engine and allow to idle reaching normal operating temperature. If voltage drop is less than .1 volt, replace upstream oxygen sensor. Perform TEST VER-5A . If voltage drop is .1 volt or more, repair poor connection causing high resistance on the upstream oxygen sensor signal circuit (Black/Dark Green wire) between upstream oxygen sensor and PCM. Perform TEST VER-5A .
  5. Start engine. Check for exhaust leaks between engine and catalytic converter. If no exhaust leaks exist, go to next step. If exhaust leaks exist, repair exhaust system as necessary. Perform TEST VER-5A .
  6. Inspect wiring and connectors between upstream oxygen sensor and PCM. Inspect related wiring harnesses and connectors. Refer to Technical Service Bulletins (TSBs) for related problems. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary. Perform TEST VER-5A .
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