Mitsubishi Repair: Mitusbishi sensors concern, intake air temp, coolant temp

Question
Thanks for the answer last time Linda.  Now my problem is the emission sensors.  I get error codes for the Intake air temp, Idle speed control motor position, Engine coolant temp and Barometric pressure sensors.  I've replaced the sensors and replaced the ECU.  Somehow their signals aren't getting to the ECU.  My wiring schematic refers to a MFI Control Unit. That schematic shows a box with those sensors in it called INPUT SIGNAL and a big black arrow pointing to the MFI Control Unit.  Where the heck is this unit?  What should I check?  Is there somewhere that explains how to read a schematic?  Thanks so much, Greg

Answer
Greg: I wanted you to know I am doing some checking on this. It has been a busy week-end but never to busy for my questions. I did not want you to think I had forgotten you. One thing you might try to buy is a manual called Engine Code Manual,I had one but someone has borrowed it and I am trying to find out who has it. Chilton makes this. So you might try that.I do know the MFI stands for Mulitiport Fuel Injection. The pressure sender senses manifold pressure so that the MFI can map fuel input/engine speed/road speed to fuel consumption. So if I can find my book... see what happens but I shall get back to you. Hope this helps some and God bless: Linda