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Home >> Buick >> 2002 >> Century Custom >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.1L Engine >> Diagnostic Tests >> DTC P0171: Lean Fuel Trim System (Bank 1) >> Test Description

Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

  1. 5

    If no condition was found, diagnose fuel system for a possible fuel condition.
  2. 6

    If no conditions are found, a worn cam, worn intake, or exhaust valves, or other engine mechanical failures may be at fault.