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