Diagnostic Aids
WARNING: This page is about a different car, the 2000 Isuzu VehiCROSS, 2000 Isuzu Trooper, 2000 Isuzu Rodeo, 2000 Isuzu Amigo, and 2000 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.
An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness.
Using scan tool, monitor signal voltage while wiggling HO2S related connectors and wiring harness with a warm engine running at part throttle in closed loop. If a failure is induced, signal voltage will change from normal fluctuating voltage to a fixed voltage. A change in voltage will assist in isolating location of fault. DO NOT solder HO2S wires.