I misread the IAT sensor part, my bad, guilty as usual 
My ECU is tuned accordingly so that plays a big part here, and yes it's an EFi of course.
and no my current car doesn't have the 'so called cold air intake' that most people have here, it's a Simota and it goes down to the bumper vent 
My civic however has the Simota Aeroform Air Intake, still there's increase in economy, but again, the ecu programming hits in here. Here's a picture of it from my build thread:

The filter was a brand new K&N with a Simota assembly, but the car's ecu was programmed due to the upgrades, which were useless without a tune.
The one posted in the picture is not a CAI if that's an original picture, it's more of a short ram.