Tolerance? A sensor value is what it is. The ECM can't magically create it's own values for a given input and ignore what it truly reads. Not legally anyway. If I push a #3 on a calculator I expect to get a 3 on the display and not whatever the processor decides to give me. The EPA will never allow manufacturers to do this or else emissions standards wouldn't mean a thing and there would be no need for computer controlled engine management systems nor would any car meet modern fuel mileage standards. Not being a jerk guys but you really should invest some time in EFI 101 and learn what each sensor is, the value scale and type of signal it transmits and what the software in the ECM does with the information. You'll have a whole new outlook on what these tuners actually do and the amount of time they invest in providing the products that produce more power safely and still allow you to LEGALLY pass annual inspection. Not to mention its far more fun to actually know how your car works and what's going on with your modern computer controlled hotrod.