Diagnostic Aids
WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
If DTC P0441, P0446, P0451, P0452 or P0453 is output after DTC P0442 or P0456, first troubleshoot DTC P0441, P0446, P0451, P0452 or P0453. If no more malfunctions are detected, troubleshoot DTC P0441 or P0456 next. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected. When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.