i just put in a fujita CAI on my accord 2006 4cyl and it seems like 1-3 gears gained acceleration but seems like 4-5 gears take longer to accelerate. Anyone with answer????

 

Are you talking performance wise with the intake installed vs stock airbox? With the intake, you should have a power gain throughout the RPM band. I am thinking it might just be in your head.......

 

It wouldn't make sense that and new intake would affect only the top 2 gears, and for it to slow the car down at all would be strange in itself.... the only way you would know for sure is if you timed it with the new intake then replaced it with stock and timed it again.... I doubt it slowed down your car but if somehow it did that would be the only way to know for sure...