Diagnostic Aids
WARNING: This page is about a different car, the 2000 Isuzu Hombre. However, it is still accessible from the selected car via links, so may be relevant.
If DTC P0171 cannot be duplicated, problem may have been caused by engine running out of fuel. A fuel delivery malfunction will cause DTC to set. Check power brake booster check valve. Check all items that can cause a lean condition.
An intermittent problem can be caused by misrouted harness, rubbed-through wire insulation or broken wire inside insulation. DO NOT attempt to repair damaged oxygen sensor connector or wiring. If damage is detected, replace oxygen sensor.