Also, make sure your idle is set correctly. Should be 800 for your year (unless it's an automatic).
One other thing if you don't find corroded connectors like all the rest of us play with. There is an adjustment on the outside of the AFM that controls idle enrichment. If your plugs are in good shape, you have no vacuum leaks, and all your sensors and connectors are working right, you might try having the AFM adjusted. Someone could have monkeyed with it. Normally I would say leave it alone, but if all else fails...
Screwing the screw in will make for a richer mix. Screwing it out will lean it out. Unless you have the right equipment, you won't know if you are making any worthwhile changes.
One other thing. Check that your TPS is working correctly. At idle, the idle contacts should be making. As soon as the throttle moves off idle, they should break, and no other contacts should be making. At 35% or so of throttle movement, the WOT contacts should be making. These two contacts allow for smoother running at idle, and more fuel at wide open throttle (keeping it from leaning out). If misadjusted, you can have problems. Clean the contacts, and if needed adjust. If you adjust and the car starts running different, be sure to readjust your idle to the proper rpm.
Basically though, a clean air filter, fresh oil, new plugs, and a good PCV valve should see you through the emmisions tests.