DTC P2197 O2 Sensor Signal Biased/Stuck Lean (Bank 2 Sensor 1): Wiring Diagram

Engine Electrical System ENGINE TYPE EZ (WITHOUT PUSH BUTTON START) <Ref. to ENGINE PERFORMANCE (Legacy), ENGINE PERFORMANCE (Outback), Engine Electrical System.>
Engine Electrical System ENGINE TYPE EZ (WITH PUSH BUTTON START) <Ref. to ENGINE PERFORMANCE (Legacy), ENGINE PERFORMANCE (Outback), Engine Electrical System.>

Fig 1: Engine Electrical System - Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTICS PROCEDURE

Step	Check	Yes	No
1 CHECK FRONT OXYGEN (A/F) SENSOR CONNECTOR AND COUPLING CONNECTOR.	Has water entered the connector?	Completely remove any water inside.	Go to step 2.
2 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM and front oxygen (A/F) sensor. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector. Connector & terminal (E158) No. 45 - (E24) No. 3: (E158) No. 44 - (E24) No. 4:	Is the resistance less than 1 Ω?	Go to step 3.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM connector and front oxygen (A/F) sensor connector Poor contact of coupling connector
3 CHECK FOR POOR CONTACT. Check for poor contact of the front oxygen (A/F) sensor connector.	Is there poor contact of front oxygen (A/F) sensor connector?	Repair the poor contact of front oxygen (A/F) sensor connector.	Replace the front oxygen (A/F) sensor. <Ref. to FRONT OXYGEN (A/F) SENSOR .>