1994 Acura Legend exhaust smell

Its a 94 acura legend and there is a exhaust smell coming from the air vents when it is drove, mainly in the morning when its first started and only does it while driving. It wasnt that bad at first but is getting worse with time and I have acually seen smoke coming from vents at times and the smell somtimes is unbearable it smells like exhaust or at times like rotten eggs? I was thinking maby the catalic converter is stopped up? The car doesnt overheat or run hot, any one with an answer will be of great help before I pass out lol thanks guys.