Can I have a Petit Larceny conviction in VA sealed, so prospective employers are not able to see it? It was in 2004.

The general rule in Virginia is that all misdemeanor and felony convictions stay on your record permanently.  It is technically possible to petition the Governor for a pardon, which would then allow expungement (or removal) of the records of arrest and prosecution, but an attorney would need to know a great deal more about the circumstances of your case to give an informed opinion as to the chances of success in petitioning for such a pardon.  If you choose to explore this route I caution you to question your attorney very thoroughly before paying someone to petition on your behalf.