2. Check HO2S2 Ground Circuit For Open And Short

1. Disconnect heated oxygen sensor 2 harness connector.
2. Check harness continuity between HO2S2 terminal 4 and ground.

   Refer to Wiring Diagram.

   1. Continuity should exist. 
3. Also check harness for short to power.

OK or NG 

OK: GO TO 4. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT .

NG: GO TO 3.