Not necessarily. I'm pretty sure you can buy the MAP sensor on it's own, as you can get uprated versions, and the Megasquirt gas standalone uses various different types too.
You don't say if yours is 1Z or AHU, but the Bosch number for the sensor in the 1Z ECU is 0 273 003 212. If you have an AHU let me know as I have a spare ECU I can look at to save you taking yours apart if it's still on the car :wink:
It may be worth checking with the Megasquirt suppliers and forums to see if one of theirs is compatible. Also have a search for DigiKey as they supply the individual components for the MS.
Mikki x