Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionOxygen Sensor Heater Power Source Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Disconnect the oxygen sensor lead connector and connect
the measuring adapter [A] between these connectors
as shown in the fig ...
Separator Operation Test
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions. Turn the ignition
switch OFF. Do not smoke. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light.
...
Check 3-7 Stop Watch Inspection
Connect the leads in the same circuit as Check 3-2.
By pushing the upper button each time to set the stop
watch mode.
Connect the insulated auxiliary lead processed insulation
to the terminal [13] as shown in the figure, then stop watch
start to count.
While count the stop watch, conn ...