It us to be relatively easy for a criminal defendant to try and withdraw his or her plea prior to a sentencing (a sentencing date usually takes place about 3-4 weeks after a plea is made). The rule that controls how it is done indicates that prior to sentencing such motions should probably be granted (Ohio law from the Supreme Court of Ohio says that pre-sentencing motions to withdraw a plea “should be freely and liberally granted”). However, more and more trial courts (and appellate courts) are, in our opinion, finding more and more reasons to deny these plea withdrawal motions - even if they are filed before sentencing. For example, a Court in Canton, Ohio (Stark County) just did this on a case involving a weapons charge. Our advice: Assume that you are locked into your plea at the time you plea - and that a trial court will be easily able to prevent you from withdrawing that plea even prior to your sentencing.
Get a second opinion if you can before you plea.