DTC P0134/P0136 - O2S Circuit, No Activity Detected

Install scan tool. Start engine and check if DTC P0134 or P0136 is present. If DTC is present, go to next step. If DTC is not present, problem is intermittent.
Turn ignition off. Disconnect affected O2S harness connector. Turn ignition on. Using DVOM, check voltage between affected O2S harness connector terminal No. 4 and ground. If battery voltage is present, go to next step. If battery is not present, check circuit between terminal No. 4 and fuel pump relay. See appropriate wiring diagram in WIRING DIAGRAMS section.
Turn ignition off. Disconnect ECM harness connector. Check for continuity between ECM harness connector terminal No. 12 (front O2S) or terminal No. 39 (rear O2S) and O2S harness connector terminal No. 1. If continuity is not present, check for open in circuit between O2S and ECM. If circuit is okay, go to next step.
Reconnect ECM harness connector. Check for continuity between O2S harness connector terminal No. 2 and ground. Continuity should be present. If continuity is present, go to next step. If continuity is not present, check circuit between O2S harness connector terminal No. 2 and ECM.
Check fuel injector(s), fuel pressure regulator, MAF sensor, ECT sensor, ignition system or air/fuel ratio. See related DTC or SYSTEM/COMPONENT TESTS article. Repair as necessary. If components are okay, go to next step.
Clear DTC. See CLEARING DTC(S) . Retest system. If DTC resets, replace ECM.