Section 109 (Engine Controls - Self-Diagnostics): Summary: Notes
WARNING: This page is about a different car, the 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
If no diagnostic trouble codes are present, but driveability symptoms or intermittent problems exist, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent procedures.