Specification :

Repairs to the emissions-control systems of a 1996 or newer (OBD-II)
vehicle cause the vehicle's computer (ECU) memory to be cleared.
The vehicle must go through a drive cycle to allow the ECU to
perform a series of tests to ensure that the repair was successful,
and before a state mandated emissions test can be conducted.

Modern vehicles lack equipment to indicate whether the tests have been completed.
As a result, often times the customer will bring the vehicle back to the repair
shop for retest before all the required tests by the ECU are complete.
This causes the vehicle to be rejected from testing because the computer
is not ready, leading to lost time and frustration to both the customer and the technician.

The purpose of the Ready-or-Not test tool is to provide an easy way for
automotive technicians to determine whether an OBD-II vehicle is ready
for an emissions test. The device can be loaned to a motorist to aid
them in knowing when to return for testing

One of the most commonly asked questions that shops receive after repairing
an OBD-II compliant vehicle is ¡°Why can¡¯t you retest my car now?¡±,
followed by ¡°Just drive my car? How will I know when it is ready?¡±

The Ready-or-Not test tool helps answer this question.
It can be used by automotive technicians to determine whether
an OBD-II compliant vehicle is ready to receive an OBD-II test.
The device connects to the vehicle's diagnostic link connector (DLC),
and alerts the user when the vehicle is ready for the OBD-II test.
It include ISO15765-4 (CAN), ISO14230-4 (KWP2000), ISO9141-2, J1850 VPW, J1850 PWM
and Monitor statuses(CAT, EVAP, SEC. AIR, O2, O2 HTR, EGR).