Things You Should Know About the Readiness Monitors
A number of factors, including erasing of diagnostic trouble codes (DTCs) with a code reader or a disconnected battery, check Engine Light can cause Readiness Monitors being set to “Not Ready”. In order for the OBD monitor system to become ready, the vehicle should be driven under a variety of normal operating conditions. You will need to drive up to 200 miles, in order for the OBD2 to set all of the sensor reading to ( Ready Status ).
