I have a 2002 RSX-S with 107k and when I'm driving normal switch gears at around 3500-4000 there is a 1/2 sec minor sputter and loss of power...from 1st-2nd 2nd-3rd and 3rd-4th only. During WOT it runs perfect. I changed the plugs to oem ngk iridiums, oil change at acura, tranny flush at acura. I also have a 2.5 catback, k&n typhoon intake. Sputtering was occuring before mods too. It happens when its cold and at NOT. I also reset my ecu after mods and still sputters. Could it be my ignition coils going bad? Or my fuel filter dirty in the pump? I do notice a back fire when comming down from high rpm only sometimes though. There are no CELs. During WOT it runs good only while shifting at normal speeds I feel/hear a sputter and what seems like a slight clutch slip... Any help would be appreciated.