Diagnosis & Repair
WARNING: This page is about a different car, the 2003 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.
Check for any other DTCs. If other DTCs exist, diagnose and repair those DTCs first and retest. If only DTC P0121 exists, replace TP sensor.