Possible Causes
| Possible Causes |
|---|
| EXHAUST LEAK |
| (K243) O2 2/2 SIGNAL CIRCUIT |
| (K904) O2 RETURN DOWNSTREAM CIRCUIT |
| 2/2 O2 SENSOR |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .