I'm installing a maft pro on a 90 supra turbo. As far as I can tell the car is not equipped with a HAC. Ive checked wiring diagrams from different sourses and none of them show a HAC circuit or modified ECU. The only gray wires on my ECU are ign. sw. and VF signal. The direction for the maft show a gray and a white wire extending from the ecu. Do some cars not have this and should you just not hook up the gray wire on the maft harness.
maft pro HAC question
- Thread starter viraco
- Start date
The HAC is integral to the ECU for most 1989 models, and all 1990 - 1992 models. The wires described in the installation instructions are only there if you have sent your ECU in to be modified by Full Throttle.
You can do the mod yourself (as long as you're not squeemish when it comes to modifying a circuit and soldering). The info's been posted here by DrJonez and a couple others a few times, you should be able to find it if you dig a little... there are even pictures! 
its easy to do yourself. Log as you got good eyes... you have to cut a printed circut, ______ from that to ___ ____ that... hehe just takes a razer knife and good eyes... then you just soder 2 wires in the board and you are done... real easy....
Depends. If you live at sea level and don't change altitude much, it doesn't matter. However, if you live up high, or if you enjoy driving in the mountains, yes, it will affect you.