Performance chips...can i not let ford know?

[98SteedaGT]

I would think since the chip alters the signals going to the injectors and plugs, etc. Then a tech with a keen eye could tell that the main computer isn't the one controlling the engine. In the computer field we can tell what mods a computer has just by the way it responds to certain things. That, and there maybe something that comes down into the diagnostic port too.