Toyota 2GR-FE Manual page 341

HO2S high voltage (Extremely high) (P0138, P0158):
Duration that following condition is met:
Rear HO2S voltage
COMPONENT OPERATING RANGE
Duration that following condition is met:
Heated oxygen sensor voltage
MONITOR RESULT
Refer to CHECKING MONITOR STATUS (See page ES-25).
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
10 seconds or more
1.2 V or more
30 seconds or more
Varies between 0.1 and 0.9 V
ES–185
ES