DTC P0134: Heated O2 Sensor (Ho2S) No. 1 CKT Activity Insufficient

Connect scan tool to Data Link Connector (DLC). Drive vehicle for at least 2 minutes at 2000 RPM or greater with engine coolant at 158°F (70°C) or greater. Observe OXYGEN SENSOR B1 S1 parameter on scan tool. If voltage varies at greater than 0.5 volt, check for an intermittent problem. See TESTS W/O CODES article. If voltage is not as specified, go to next step.
Turn ignition off. Disconnect HO2S No. 1 harness connector. Start engine. Using a voltmeter, measure voltage between terminals No. 1 and 2 of HO2S No. 1 harness connector while sharply increasing engine RPM and returning to idle. See Figure . If voltage is 0.5 volt or greater, check Red/Blue wire or Gray/Yellow wire between PCM and HO2S No. 1 for an open or poor connection. Repair as necessary. If wire and connections are okay, replace PCM. Retest system.