The Honda Civic Si 2002, like other OBDII-equipped vehicles, requires specific driving conditions to set its readiness monitors for emissions testing. If your Civic Si has failed a smog test due to incomplete monitors, following a proper drive cycle is crucial. This guide outlines the OBDII drive cycle to help prepare your 2002 Honda Civic Si for a smog check.
OBDII Drive Cycle Steps for a 2002 Honda Civic Si
This drive cycle should be performed with a cold engine, meaning the coolant temperature is below 122°F and the coolant and air temperature sensor readings are within 11°F of each other. Important: Avoid turning the ignition key on before the cold start to ensure the heated oxygen sensor diagnostic runs correctly.
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Initial Idle: Immediately after starting the engine, let it idle in Drive for 2.5 minutes with the A/C and rear defroster turned on. This phase allows the OBDII system to check the oxygen sensor heater circuits, air pump, and evaporative emission (EVAP) purge system.
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Acceleration and Steady State Driving: Turn off the A/C and rear defroster. Accelerate to 55 mph using approximately half throttle. This tests for ignition misfire, fuel trim, and canister purge. Maintain a constant speed of 55 mph for three minutes. During this period, the OBDII system monitors the exhaust gas recirculation (EGR) system, air pump, oxygen sensors, and canister purge.
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Deceleration: Decelerate to 20 mph without using the brakes or depressing the clutch. Allow the vehicle to coast down. This step checks the EGR and purge functions.
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Second Acceleration and Steady State Driving: Accelerate again to 55-60 mph using half throttle. This repeats the misfire, fuel trim, and purge checks.
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Extended Steady State Driving: Maintain a steady speed of 55-60 mph for five minutes. This extended period allows the OBDII system to monitor catalytic converter efficiency, misfire, EGR, fuel trim, oxygen sensors, and purge functions.
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Final Deceleration: Coast down to a complete stop without applying the brakes. This performs a final check of the EGR and canister purge system.
Completing this drive cycle should set the readiness monitors in your 2002 Honda Civic Si, allowing it to pass the OBDII portion of a smog inspection. If the monitors still do not set after completing the drive cycle, it may indicate a problem with the emissions system requiring further diagnosis by a qualified technician.
