I can assure you on BF>FG they can tell it has been flashed, but they need a special diagnostic tool, that the Ford warranty inspector has.

If you put a rod through the block, I can guarantee that Ford will send their warranty inspector to check if it has been fiddled with.

The BA's are a different story as they seem to rely on bluff to deny warranty.

If you want proof check out another topic that started recently. A bloke had a warranty claim knocked back due to a flash tune

As I found out 3 days ago they can detect Flash Tunes in BF's, supposable not BA.

Will need to take to your Tuner to get properally flushed.

I can tell you from personal experience if you reload the standard program back in before taking it into Ford they will not be able to conclusively detect that you ever had a flash tune in there.

Ohhh trust me they still can.

Edited March 27, 200917 yr by Plugg3r

Sure can on a bf had my warranty claim denied when ford inspector came out. Said it had been flashed 30 times haha. no more drive train warranty for me

There is no way for the Tuner to professionally "Flush" the evidence of a flash tune.