i have a 2005 mazda3i auto tran, Iinstalled anAEM CAI months ago..now my car is getting about 240-250 miles PER TANK!!! i noticed a drop before, but this seems WAYYY to low! anyone know what could be a problem? I drive with a light foot (most of the time), alsomy carseems to drive really sluggish at times and other times it seems like it has a lil punch in it.Im beginning to notice more and more issues with my 3. Time for a new car maybe? haha.

 

Have you tried resetting the ECU? It may be worht a shot.
Disconnect the neg batt terminal and leave it that way for @ least 10 mins. During this time, also try turning on the ignition, radio, blower motor, anything that might draw power through the ECU just to make sure all the capacitors in the system are fully discharged. Then reconnect and see if that solves your problem.

 

Like virgin1 said try resetting the ECU. Oh and for discharging the capacitors you should be able to do that by pushing and holding the brake pedal a few times.

If that doesn't work then I would ask your dealer if there's a ECU reflash available for your car. If there is then remove your CAI and go get them to do it for you. You could also try removing the CAI and see if it does better after the reset.... I doubt that's it, but it's always something to try.

Have you gotten any CEL's?