How to Set Monitors for a Smog Check

1. Pre-Drive Checks

   • Ensure your fuel tank is between 30% and 70% full.

   • Verify there are no pending diagnostic trouble codes (DTCs) using an OBD II scanner.

   • Ensure the vehicle is properly maintained and that all necessary repairs are completed.

2. Starting the Drive Cycle

   • Begin with a cold start (the vehicle should be off for at least eight hours). Start the engine and let it idle for 2-3 minutes.

   • Drive at a steady speed of 20-30 mph for about three minutes. This helps warm up the engine and the oxygen sensors.

3. Highway Driving

   • Accelerate smoothly to 55 mph and maintain this speed for at least 3-5 minutes. This allows the vehicle's catalytic converter to reach its operating temperature.

   • Avoid using cruise control to ensure natural speed variations.

4. Deceleration

   • Allow the vehicle to decelerate naturally without using the brakes (coast down) from 55 mph to 20 mph. This process helps test the oxygen sensor and EGR (Exhaust Gas Recirculation) systems.

5. City Driving

   • Drive at a steady speed of 25 mph for 2 minutes, then stop and idle for 3 minutes.

   • Repeat the stop-and-go driving to simulate typical city traffic conditions.

6. Cooldown Period

   • Park the vehicle and let it sit for at least 30 minutes. This period allows the evaporative system monitor to run its tests.

7. Recheck Monitors

   • After completing the drive cycle, use an OBD II scanner to check if all monitors are set. The critical monitors for the Smog Check include the catalytic converter, oxygen sensors, EGR system, and evaporative system.

Tips for Successful Monitor Setting

• Consistency: Drive the vehicle consistently during the cycle. Sudden stops, hard accelerations, or varying speeds can interrupt the monitor setting process.

• Multiple Attempts: It may take several attempts to complete all the monitors, especially if the vehicle's battery was recently disconnected.

• Professional Help: If you're having trouble setting the monitors, consider seeking help from Hensley's Auto.  If you have driven your vehicle over 500 miles we can run a diagnostic to see why the moniitors are not setting.

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Conclusion

Setting the monitors through a proper drive cycle is crucial for passing California's Smog Check Program. By following the outlined steps and ensuring all readiness monitors are complete, you can avoid the inconvenience of a failed smog test. Regular vehicle maintenance and adherence to the drive cycle procedures will help keep your vehicle in compliance with emissions standards and contribute to a cleaner environment.