The catalyst monitor on many Toyota vehicles can be difficult to complete. That’s why it’s important to follow the Toyota recommended drive cycle after performing actions that are known to clear your Toyota’s computer memory.
Remember, all on-board diagnostic monitors are cleared when the battery is disconnected, or when the power train control module (PCM) is cleared with a scan tool.
CATALYST MONITOR DRIVE CYCLE INSTRUCTIONS
- Do not turn off the ignition switch during the test procedure.
- Allow the vehicle to run at idle until warmed up.
- Drive at a steady speed between 40 and 70 MPH for 10 minutes. It’s a good idea to stay in the middle of this range, so 55 MPH is optimal.
- It may take several attempts and warm up cycles to complete the drive cycle.