I don't know how far off from the standards you were or the history of your car. However, if it is running well, in-tune, and has a history of passing, then I suggest you drive the car until the gas is empty, put in a large bottle of Chevron Techron, and drive the car HARD until you are near empty. With the car hot and warmed-up, go to the emissions station. At the emissions station try to keep the car running on/off while waiting (don't gun it too hard or let it idle for ever, just keep it hot) then get the test done.

The average layperson is always seeking something they can dump in the gas tank, oil, or radiator to make a magical fix. However, in some cases, it really matters in the case of fuel and intake injection cleaning with a product like Techron. You can put thousands of dollars into a car to get it through emissions but in some cases just following the advice above will have it pass. I have seen it and experienced it.