I hope you have disclosed your two DUIs and your overstay issue on your visa application. In which case, they would have issued the visa by mistake, and you should return it. Come clean, return your visa, then you can apply for rehabilitation because over five years have passed (consult with lawyer for the specifics, since nobody here is an expert).
This is important, especially if you're planning to apply for any permanent status in Canada. Let's say you lie your way to your citizenship. Even years and decades after naturalization, they can always look back to your application for PR and visitor's visa, and when they find out that you have knowingly lied (especially in matters which directly affect admissibility), then they would very likely start the process to revoke your citizenship.
And as
@scylla mentioned, rehabilitation is something you need to apply for. To be deemed rehabilitated, 10 years must have passed.
As it is right now, you are inadmissible (DUI is hybrid offence in Canada, and foreign nationals are automatically inadmissible if they have been convicted of hybrid offences).
(2) A foreign national is inadmissible on grounds of criminality for
- (a) having been convicted in Canada of an offence under an Act of Parliament punishable by way of indictment, or of two offences under any Act of Parliament not arising out of a single occurrence;
- (b) having been convicted outside Canada of an offence that, if committed in Canada, would constitute an indictable offence under an Act of Parliament, or of two offences not arising out of a single occurrence that, if committed in Canada, would constitute offences under an Act of Parliament;
- (c) committing an act outside Canada that is an offence in the place where it was committed and that, if committed in Canada, would constitute an indictable offence under an Act of Parliament; or
- (d) committing, on entering Canada, an offence under an Act of Parliament prescribed by regulations.
http://laws-lois.justice.gc.ca/eng/acts/I-2.5/section-36.html
Deportation from the US alone by itself does not make you inadmissible to Canada (though it would make it that much harder to obtain a visit visa). Your DUIs, however, do.