Diagnosis & Repair
WARNING: This page is about a different car, the 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
Retrieve trouble codes. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If only DTC P0121 is displayed, replace TP sensor and retest system. If other codes are displayed, diagnose and repair those codes first and retest system.