One possibility I read there:
>
> Step D. Drive your vehicle for one week under normal driving conditions.
> During this period the emissions computer is gathering data and
> re-learning your vehicle's emissions components and systems. The emissions
> computer OBDII (on-board diagnostics) system must complete at least one
> drive cycle (in some cases two or three). A drive cycle is a sequence of
> internal tests which the emissions computer runs while your vehicle is
> being driven. This insures all emissions systems are functioning properly.
> Proper "readiness flags" are set as the computer completes it's cycles.
> Test cycles are unique to a vehicle. Certain cycles run under very strict
> parameters, and may require extended driving time to trigger on. Cycle
> data and readiness flag information is available through your dealership's
> service department. The data vary widely.
>
>
> My questions.
>
> 1) Does Step D make sense, given that I'd erased the codes? If I do
> drive the car for a few days like this, should I be able to pass the test? >
> 2) If I erased all the codes, are they really all erased? Or, is there
> still some log about them? That they were there, I erased them, and they
> are just flagged inactive now?
>
>
> Thanks a lot!
It knows the codes have been reset recently. And it also has a count of how many 'driving cycles' are on the ECU. In Mass I think it requires 4 driving cycles in order to pass (for some reason the number 2 is stuck in my head, but I think they have made it 4.) The ECU keeps track of driving cycles and the OBDII reader counts them.
Drive the thing for a couple days and then go for a retest. As long as the MIL is off, it should pass.