I received a deferred sentence for my second DUI in may 2010. My probation ends October 1 2013.

Usually when this type of question is asked there is a reason. But assuming there is nothing in your system as you indicate in your question, then you have nothing to worry about. Sometimes machines malfunction and if that is your concern then contact your PO right away. If you can't get in touch with the PO, go to the local police station and take a PBT and have it documented. Hope this helps.

My advice is to avoid putting yourself in the position to find out. You're only on probation for 3 more months. Tough it out and put this behind you. Good luck. Jasen Nielsen

You never know what a judge will do. You are assuming a situation where there are many variables, such as level of alcohol. So, just keep your nose clean for a few more months, and then you are free!