As it is stated, the magnum chip will offset the air intake temperature, make the ECU think that the air is cooler and then inject more fuel. In the drawing diagram, I see that it also connect to the O2 sensor but not sure how they modulate that signal. Look like there is only one place to tune which is the variable resistor.

The Fatduc only offsets the O2 sensor and the price is half of the Magnum.

Mine is DD1200 with Arrow cans, thinking abt those above parts. Anyone has experience on that?