u can expunge a felony provided it isn't DUI related or sexual in nature. Also, u must not have been arrested/charged w/any new crimes. Certain crimes, u will have to wait 10 years.
However, if u r a 1st time offender and your felony conviction is NON-violent (for ex., ID theft, 1st degree retail theft), u can get your expungement after 3 years.