"I bought a PTI. It didn’t come with any instructions with what to do with the supplied MAP sensor. What am I supposed to do with it? Where does it go? What do I do with my stock MAP sensor?"
The PTI unit is intended for forced induction applications (i.e. turbo/super-chargers). Since these applications are highly customized and unique, we leave it up to the end user’s best judgment for selecting an ideal location to mount the supplied 3-bar MAP/IAT sensor. This sensor is not intended to replace any stock sensors that may or may not be originally equipped on the vehicle.
In order for the sensor to ever see vacuum at low RPM/low throttle, it must be mounted or connected to a pressure reference tube that is between the throttle plates and intake valves. Otherwise if its pressure reference comes from before the throttle plates, the sensor will only ever see atmospheric pressure at its lowest pressure up to the boosted pressures. It will not be able to see vacuum pressures if the pressure reference comes before the throttle plates.