[dcb]

Was the engine light on?

Around here (ill noise) you want to make sure that the car is together enough for that to be off before you go for emissions testing, otherwise they want you to have a "mechanic" sign off on it before bringing it back.

They basically do an obd test here, if your scanner (or the one you borrow from autozone, or your scangauge, or your hacked up obduino) indicates all the rediness monitors have passed AND your engine light is off, then you are pretty sure to pass the "real" emissions test.

Also, the monitors take a few miles to pass after the battery is disconnected, so don't unhook your battery right before a test.