How to backrev AP firmware

[KoukiS14]

I managed to successfully backrev the firmware on my AP this morning from 1.4.0.1-11124 to 1.4.0.0-10793. This may be useful for those experiencing problems with FFS running lean after the shift. Here's the method I used, but this is all at your own risk. If you brick your AP, don't come crying to me.

1. Make sure you DON'T have internet connectivity. You have to do this in offline mode with AP Updater.

2. If you look in C:\Program Files\AccessPORT\AccessPORT Updater\AP-MAZ-002, you'll see all of the firmware versions you've ever installed on your AP using your computer. Hopefully you'll have a copy of 1.4.0.0-10793, or whatever version you choose to use. Delete (or .old) the contents of the AP-MAZ-002 folder, EXCEPT for the folder containing the firmware load you choose to use. Copy the version.txt file from the firmware load folder to the AP-MAZ-002 folder. Your AP-MAZ-002 folder should now contain just the 1.4.0.0-10793 firmware folder and the version.txt file from the 1.4.0.0-10793 folder.

3. Launch AP Updater, click okay to offline mode, and click the Update button. It should proceed like normal, but will install what it thinks is the most recent version of firmware, which is indicated by the version.txt file in the AP-MAZ-002 folder, and references the actual firmware load folder located within the AP-MAZ-002 folder.

I can't be certain, but I suspect that this method might even possibly let you update any AP with firmware for another platform, allowing you to convert a Subaru AP to an MS3 AP, etc. Not sure about that, but it's a theory. Again, if you brick your AP, don't complain to me.

[MS3Zoom24]

has anyone else done this,

and OP how has this worked for you??

Any problems or what not???

[KoukiS14]

No problems with the firmware downgrade at all. It's only partially (85%) fixed the post shift lean condition with FFS though.

[itzl0l]

should be stickied

[jayspeed3]

WORKED PERFECTLY!!!

Originally Posted by itzl0l should be stickied

+ONE-MILLION

[KoukiS14]

As far as an FFS lean fix, in the end, increasing the MAF curve by 2 to 4 percent from 3 volts up is the best solution. It worked better than the old firmware alone, and the fix persists across new firmware versions.

[joey]

This does not work with AP Manager 2xxx :'(