I didnt p my smog check! I have a 2001 Nissan Xterra.?

I didnt p because there was a reading showing "Catalyst system Efficiency "and the "intake Air Temperature Circuit Malfunction? Ok what the hell does that mean? Also what does it mean when the MIL commanded is on? The man that did the smog, said my check engine light should be on because his smog tester machine is showing it but it is not. Help!