perhaps this was simply adding a maf sensor to a stock 95 mustang 5.0 it would make no sense to just install that without supporting mods. it would be similar to adding a 3 inch muffler on a stock 1.5 exhaust its done absolutely nothing and perhaps hurt power. although im by no means a expert. basicly every car needs 3 things to make power air fuel and spark. too much spark does nothing without fuel and air. to much fuel hurts power and the same with to much air. i dont think this will affect your car and you probably did gain power you have supporting mods.
if anything the lesson i learned reading that was that i would be better off amassing a large amount of after market performance parts installing it all at once and tuning it. itll probably put a bigger smile on my face getting a all at once 50hp increase than a progressive increase 5-10-15hp increments
Our computers are far from crap infact our processors are far superior than the fox. Now as far as the tune, well it has alot to be desired. If you plan on doing HCi stick w/ what ya have and get a dyno tune and chip burnt. A9l swap is a thing of the past no need for it these days. JMO