We're going to recommend trying the Honda Civic Hybrid drive cycle we indicate below. It should get the catalyst monitor ready for the smog inspection. If you've tried the drive cycle already and have still been unable to get all the monitors complete, we'll have to recommend a smog check repair station or Honda dealer take a closer look. Even though the check engine light is no longer illuminated, there may be a sensor which is partially failing and stopping the catalyst monitor from becoming Ready or Complete.
Typically driving 200-300 miles through various traffic conditions and over the course of a few days is enough to get the drive cycle to initiate. Simply driving an extend length of time however does not necessarily make the monitors complete. Your Hybrid Civic's engine control unit performs internal self-tests in order to ensure the engine is running efficiently and not polluting. These self-tests are called Monitors. The entire process of self-testing various emission control systems is called a Drive Cycle.
Notice: Obey all traffic laws while performing drive cycles. Perform the drive cycle cautiously and at your own risk. Use a OBD-II scan tool to check the status of the monitors once you've completed the drive cycle at least once.
How To Perform a Honda Civic Hybrid Drive Cycle
The following is a Honda Civic Hybrid OBDII Drive Cycle Pattern.
Cold Start: Begin from Cold Start, and ignition in OFF position for at least 1 hour. Ensure your vehicle's fuel tank is between 1/4 and 3/4 full and engine coolant temperature is below 122°F and within 11°F of the ambient air temperature. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
Idle Time: Start and run your Civic’s engine (do not drive) for 3 minutes with the air conditioner on and rear defroster on. During this period the ECU will be initiating the Oxygen Sensor Heater self-test, Air Injection System Passive Air test, EVAP Purge "No Flow" test, Misfire Detection.
Acceleration: Turn off the air conditioner and rear defroster and begin driving. As soon as possible apply half throttle until 55mph is reached. The ECU will now run self-tests on the Misfire Detection, Fuel Trim, and EVAP Purge Flow.
Hold Steady: Hold your vehicle speed steady at 55mph for 3 minutes. During this time the Oxygen Sensor O2 response, Air Intrusive (AIS System), EGR Flow, Purge Valve, Misfire Detection, and Fuel Trim diagnostics will be performed.
Deceleration: During this step you want to slowly let off the accelerator pedal. Do not apply the brakes in order to slow down. It is important to let the vehicle coast along gradually slowing down to 20 mph. The ECU will once again self-test the EGR System, EVAP Purge System and Long Term Fuel Trims.
Accelerate: Accelerate again at 3/4 throttle until 55-60mph is reached. This will perform the same self-tests as during the first acceleration step.
Hold Steady: Hold steady speed once again. This time at 55mph for 5 minutes. During this time, in addition to running the self-tests as during the first HOLD STEADY step, the ECU will perform the catalyst monitor diagnostics. If the catalyst (Catalytic Converter) is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst,or in order to Complete the CAT Monitor.
Decelerate: This will perform the same diagnostics as in the first Deceleration. Remember not to use your car's brakes during deceleration.
This completes the Honda Civic Hybrid drive cycle.
