Your Ford Mustang is equipped with an On-Board Diagnostics system called OBD
II. Your Ford's OBD II computer system is designed to monitor all aspects of
its engine emission conditions and report this information to a central
database within the OBDII computer. This information is processed and
checked against the computer's pre-determined values for various inputs
levels and performance patterns of your vehicle. If any problems are found
the computer will determine whether to alert the driver or not.
If your Mustang's battery had been recently removed, replaced, disconnect
and reconnected or was dead and your Ford Mustang had to be jump started,
the emissions monitors were erased from your Ford's computer. You must drive
your Honda for at least one to two weeks before retaking the smog check.
Your Ford Mustang failed the smog check because the required (Readiness
Flag) monitors were not set or complete. So to recap... Your Ford Mustang
could fail the smog inspection if any Trouble Codes are present and the
check engine light is on, and it can also fail the smog check without the
Check Engine light on, but monitors not set. Monitors not set will not cause
your Ford's Check Engine light to turn on, but will cause it not to pass the
smog test.
In order to set the monitors you will need to drive it through 2 or 3 drive
cycles. Your car can pass the smog check. Drive cycles vary per vehicle -
usually 1-2 weeks worth of driving is enough. In some cases such as this
more driving may be necessary.
