I would think it would throw a code but there is a specific method of installing which is why i asked. I gave you the specs so i would also see what you have when the gas pedal is fully pushed. 0.68v is acceptable at rest which is why it probably isn't throwing a code, but have you worked the throttle to the maximum? I wonder if it will fault at a higher rpm. You should be able to go lower in voltage slightly.If I installed it wrong would it throw a code? Will the car not run? Cause the car runs ok with no codes right now, right now the TPS is all the way to one side and can't be adjusted anymore.
Edit: i checked mine and it's right in the middle. If you cannot get the voltage to drop below what you have now i would think there's something wrong with it, providing you put it in there in the most clockwise position and turned back counterclockwise.