An OBDII device and method and system which includes an inexpensive, user friendly way to determine a vehicle's readiness status for emissions testing. An audible or visual indication that may or may not be wirelessly connected to the tool is provided to alert the repair shop technician or driver that the vehicle has completed its drive cycle and may now be tested for compliance with state and federal emissions laws. The device also includes the ability to prevent the tool from discharging a power source of the vehicle when the device is coupled to the vehicle.