Wow! Sorry to hear that, but since it came from the factory like that then just show the paper work like your window sticker if you still have it. Question: Does your intake come with a carb legal sticker on it?
I also have a question about this as well
16gt/cs non performance package
Auto
4.10 gears
Roush CAI
Roush H-pipe
GT350 manifold and throttle body
also running a dyno tune NKG Iridium IX Spark Plugs--Heat Range 7
Bob's passenger side oil separator
Would I need to upgrade my fuel...
https://www.mustang6g.com/forums/threads/modifying-as-built-data-guide.61773/
That's the guide I used and it worked very well. Read it thoroughly and you should be good. Purchase the Bluetooth version and make sure to use a PC, not apple.
I just went through this myself a few weeks ago. When I looked at the line of code for the gear change on forscan the last box said 55xx. Once I changed it back to the correct value that code went away. I went from 3.15 to 4.10.
First I put the stock tune back on the car (no need to swap out...
Forscan changes the BCM. What does the code say?
I thought the 18 would adjust the bcm automatically from what I've read on one of the treads, but it doesn't hurt to try.
So you tuned it first and then changed the BCM afterwards?
I wonder if something changed. I had changed the gears without having a tune on it without any issues a while back and then this happened when I was trying a new tune.