[KenWittlief]

it sounds like your sensor is working perfectly - you just need to put a line in your code to read the sensor when the bot is disabled (not in comp mode, or when auto mode first begins and you know the bot is not moving) to see what the zero number is, and use that in your code.

Its impossible to get 5.0 or 0.0 volts out of a sensor that is running on 5VDC so dont worry about the extreem values.