I recently disconnected my battery and probably erased DTCs since then. I too have to go for an emissions test for my 2004. At first I thought I could use our new self-service kiosks at the MVA, but they only allow 2005 and newer vehicles due to security requirements starting with that model year. Once I found out that the kiosk (only $10 vs. the $14 they charge at the emissions inspection station) wouldn't work for my Crossfire I requested an extension on getting the test done, which I was granted. This was a good thing because it is unlikely that enough of the monitors were ready. Here is some empirical evidence on how my 9 State OBDII monitors have progressed from incomplete to OK following DTC erasure:

1. Misfire Monitor
2. Fuel System Monitor
3. Comprehensive Component Monitor

These first three checks were ready very quickly. They were OK almost immediately and certainly within the first 5 miles of driving.

4. Oxygen Sensor Monitor
5. Oxygen Sensor Heater

These two checks took a little over 40 miles to complete. I don't recall which one completed first, but they were both OK within a few miles of one another

6. EGR System Monitor

The EGR monitor took more than 50 miles to complete.

7. Secondary Air System

This monitor took around 60 miles until OK.

8. Catalyst Monitor

The catalyst tells me it's OK after 80 miles.

9. Evap System Monitor

This one is not satisfied yet after more than 85 miles not to mention quite a bit of time idling while parked. I'm not sure MD allows any incomplete test parameters, so I may be driving around in circles for a bit. Maybe a fuel fill up will help. The MD MVA website just informs you to "drive your car for a week" to ensure all the checks are complete. I'm afraid that for a Crossfire that this might mean to drive continuously for a week, LOL. There is irony in the fact that I am driving the car around emitting all these so-called greenhouse gases simply in an attempt to pass a test that is supposed to reduce greenhouse gases. I'm not actually using my Crossfire much to get from point A to point B so much anymore; it's more like cruising around in a big circle while watching for the next "OK".