How can I p the vehicle emissions test?

I have a 99 Oldsmobile Cutl. The check engine light was on last week and we got it hooked up to the OBD and the it said the code was P1665. We purchased the part and had our mechanic put it in. The check engine light went off and then back on, and finally back off. I went to get it checked yesterday and it got rejected because of the incomplete monitors: EGR, EVAP, and CATALYST. The trouble code from the OBD came up P1665 again too. The guy told me to drive it around a few days and come back. Now my check engine light is on again. What can I do to p?