The fuel injected Z's seem to pass smog (at least in my Colorado experience)fairly easy as long as you have a good running ignition system and your vacuum leaks are fixed. You should fix your leaking injector before you go to test, cuz you'll most likely fail your passive emissions with a gas leak. More then likely you only need to replace the short rubber fuel lines that connect the rail to the injectors.

 

I'll second zpeedracer's advice and add the following (also from Colorado Z emissions experience, and some from Washington state). I've never had a problem getting a Z to pass emissions, but you can make it easier on yourself:
Definitely fix that injector leak. At the very least that's a nasty fire danger.
If the car's been sitting for awhile, try to drive a tank or two (with injector cleaner, if it's not premium gas with it already added) of gas through it.
Make sure your coolant is topped up.
A fresh oil change (especially synthetic) helps on crankcase emissions.
Have a nearly full (but not overfull!) tank of gas before you go to emissions.
Double check that all the rubber hoses on the evap can are in okay shape and hooked up (not cracked, or dried up and falling off).
Make sure there aren't any obvious cracks in the vacuum lines and that they all seem to be hooked up.
Don't forget to turn off your A/C, the stereo, the fan, or any other big electrical draws.
Go on a warm day, but not ridiculously hot. Summer mornings are great and have the bonus of no line to wait in while the car cools below running temp.
Make sure the car is completely warmed up before you get to the testing station.
If your location, Frisco, is Frisco CO, and not San Francisco, then make sure the air bypass screw has been adjusted for altitude if the car came from "downhill".
Unless something really is wrong with the car, you should pass with no trouble at all.
good luck!
Dave