There is no possible way we can answer that. It will make a difference to some employers; it will not make any difference to other employers.
All background checks are not created equal, and all employers do not run background checks. Those that do, do not all look for the same things and they do not all go back the same length of time.
I strongly advise that if you are asked any questions to which a literal, truthful answer will mean revealing your conviction, you answer truthfully. (By literal I mean don't assume anything; we had one guy here a few months back who assumed that when an employer asked "Have you EVER been convicted of a felony?" the employer MEANT "within the last 10 years" - he had a felony twelve years back and answered "no" - the employer had meant exactly what they asked - EVER - and the guy was eliminated from consideration (or fired, I don't remember which) for lying on his application.) Answer the question exactly as it reads and tell the literal truth. While it MAY (we can't know for certain one way or the other; it depends on the employer) eliminate you from some jobs, if you lie and the employer finds out, that is definitely grounds to eliminate you from consideration and/or firing you if you've already been hired. Since you don't know what they're looking for in a background check (and there are a number of other ways they can find out) it's best not to give them any additional reasons to leave you off the list, like falsifying your application.
When I get back to my office, I can see whether or not your state has any restrictions on how an employer deals with convictions, but it will be tomorrow or even Tuesday before I can do that.
Good luck.
