I was wondering, I've heard not all sensors (in general) are made the same so each sensor will need to be calibrated when used.

The current implementation of using the Mitsu 3-bar MAP sensor to log boost lays out a set calibration table for people to use. Shouldn't people be calibrating and inputting their own values in those tables?

Or are all these sensors so close that the differences are minimal?

 

The differences in OEM sensors are generally very minimal. Mitsubishi doesn't calibrate every MDP/MAP sensor when they put it in, or any of the other sensors for that matter. There is likely a tolerance range that every OEM sensor is tested against before leaving the factory. If the sensor is not calibrated during it's production, it is not calibrated at all in OEM applications.

Aside from the fact that most people don't have the means to do so, the range of variation is probably not large enough to worry about.