I have an Xcal3. I reflashed my computer after my gear swap, but my battery decided to kinda die . Do i have to reflash it, or will the tune still be there even after my car had no battery for like 5 hrs.?
I'm not quite sure I understand what you are asking. Did the battery die while you were flashing the the computer, or did it die later? If it died while you were flashing the computer, you might have trouble with that PCM. If it died afterwards, you should be fine.
The computer won't "forget" a tune if it loses power. It will, however, become corrupted if power is interrupted during the flashing process.
However, you need to be VERY careful when flashing the computer that you have a good, fully charged battery. If your battery dies in the middle of the flash you're SOL. You will most likely have to get the car towed to Ford to reflash the ECU or possibly a new ECU.
I always like to pull the fuses for the fuel pump and fan. They're in the power distribution box next to the battery. The fuel pump fuse is the left column at the top; it's a small fuse (20A I think). The fan is the middle column at the top. It's a big fuse (50A I think)..