Seems like if I reset my ECU and drive it in any style, aggressive or like grandma, the car is very responsive and quick especially at WOT. Now the next time I drive it, it seems to hesitate alittle bit and there's little or no difference between giving it 1/2 throttle and WOT. If I reset it again it goes back to being fast. I don't want to reset it everyday.. What could be causing this? the MAF?
BTW I drive a 6 spd

 

Your car is probably running rich and doing a few other things until it learns all the parameters of the sensors, etc. After that, it probably optimizes itself for fuel economy and emissions.