What EXACTLY do you mean by warped?
If you damaged or "warped" the bracket that triggers the switch, then fix what was damaged or warped. Once repaired, you may still need to adjust parameter 126 Y Grid Offset. This parameter is what tells the machine how far to turn the ball screw in order to back off the limit switch once it has been triggered.
Once the problem is fixed, you will not need to reset everytime you turn the machine on.