problem with acceleration?

[SPerformance]

i have a ka24de and i have problems when accelerate i thought that the catalytic was bad but it inst i really dont now what it is since i have already change the gas filter, spark plugs, spark, some parts of the ignition but i still get the same problem the car do not have a miss its only that wont accelerate well it is very slow when acceleration and i dont now what it is so if anyone can help me i would be really thankful.