gas mileage worse after chrome intakes., i thought it was supposed to get better? Options

[Tech9ine]

hey,
I installed this chrome intakes ram air on my ST a few months ago and since I've installed it I've gotten about 100km/tank less than i used to with my stock intake. Was I wrong in thinking the gas mileage would get better if not stay the same? could i have possibly done something wrong? (it's pretty simple, i don't think i goofed on anything.)

[95CelicaST]

Perhaps it then uses more gas as it can burn more of it with the colder denser air to make more power though? Dunno, just guessing.

it only burns as much as you allow, be it by your foot or bigger injectors.

[BigAl_UK]

Perhaps it then uses more gas as it can burn more of it with the colder denser air to make more power though? Dunno, just guessing.

it only burns as much as you allow, be it by your foot or bigger injectors.

But the ecu does adjust the fueling based on not only the position of your foot but also the amount of oxygen available guaged by the temperature of the incoming air, the intake manifold pressure and the amount of O2 left after the burn determined by the lambda sensor - surely this means more air = more fuel burnt? There's something in my description about closed and open loop missing but I don't remember all that