I'm having this problem for some time now.
Usually in 2nd (and mostly 3rd) and higher gears, when gas pedal is completely pressed to the end, the car is accelerating, but when it reaches about 2100-2500rpm, the accelerating power drops for a half a second and the continues to rise normally. I took the car to the dealer but the told me it is ok.
It's really hard to show the problem to mechanic because it happens not 100% of the time - sometimes the drop is milder, sometimes it feels like brake is pressed. Could this be issue with electric or engine mechanics?
Car is Mazda 3, 2.0 petrol, 6 gear manual transmission, manufactured 2007, odomoter 130000km