Diagnosis & Repair
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 exists, diagnose and repair those DTCs first and then retest. If only DTC P0121 exists, replace TP sensor. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.