im not sure the wiring is much different to the power fc than the haltech, but again im not a tuner nor did i install it so i would only be guessing. the io expander makes you have more configurations you can use with the Haltech. again im not a tuner but to me that sounds like a good idea.. im only guessing its for making different tunes and being able to save up to 12.. someone correct me if im wrong. im with you jamie, i never got this "random cough" thing either. but i can say the car drives alot smoother with the haltech.