Possible Causes
| Possible Causes |
|---|
| OXYGEN SENSOR WIRING OR CONNECTORS |
| O2 SENSOR SIGNAL CIRCUIT |
| O2 SENSOR RETURN CIRCUIT |
| 1/2 O2 SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to *PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .