Home >> Lexus >> 2004 >> IS 300 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control System - Diagnosis >> Circuit Inspection >> DTC P0171: System too Lean (Bank 1), DTC P0172 System Too Rich (Bank 1), DTC P0174: System Too Lean (Bank 2), DTC P0175: System Too Rich (Bank 2) >> Typical Enabling Conditions