We always hear people say: Pray for me and this is permissible and there is nothing wrong in it. However, one should be careful not to make this a habit and end up asking sinners for Du’ah. Also, you may make that person feel that he is a righteous person when he is really not. We all need Du’ah from righteous people but we may better than them at times. Allah says: ”Is not He Who responds to the distressed one, when he calls Him”. Therefore, you are closer to Allah when you are in distress than any scholar or pious person. So, make Du’ah and be confident that Allah will answer you.