Hint:

How to proceed with troubleshooting
Terminals of ecuComponents
...
Air fuel ratio sensor
Components
On-vehicle inspection
Check air fuel ratio compensation system
Connect the intelligent tester to the dlc3.
Turn the ignition switch on.
Select the following menu items: data list / a/fs b1
s1 and o2s b1 s2.
Warm up the a/f sensor with the engine speed at
2,500 ...
Disassembly
Fix differential carrier sub-assembly
Fix the rear differential carrier in place with the
overhaul attachment.
Remove stud bolt
Remove the 4 stud bolts from the transmission
coupling.
Remove differential drain plug
Using a 10 mm socket hexagon wrench, remove ...