I'm not sure why you are so confused. The documentation is pretty clear. This is their diagram, as to which color wire on their box goes to which pins on the ECU.
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You just need to correct the colors for a GVR-4, which is documented pretty well in the 2GMAS-in-a-1G VFAQ:
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You don't need the wire from pin #1 of the original MAS, MAF Reset, because the MAFT doesn't supply a Reset signal. That still leaves you with the problem of tracing which Green/Yellow wire goes back to pin #16 of the ECU, so the MAFT can lock the BARO signal. (They have pin #1 of the MAS plug labeled "Idle Position Switch", just ignore it.)
You also don't need the wire from pin #4, the Green/Red striped +5 volt feed for the BARO section, as the MAFT runs off of 12 volts only, the heavy Red wire that was on pin #3 of the MAS connector.
Green/Orange is IAT, pin #8 of the ECU.
The Green/Light Blue wire that was pin #2 (to pin #10 of the ECU) is the Karman Hz wire.
For a ground to the MAFT unit, you can either source a good ground to chassis or somewhere, or I guess you could use the Sensors Ground, which is on pin #6 of the MAS, Green/Black striped wire.
