2000 V6 Accord problem
 

I just got a 2000 Accord V6 and am having a problem with the tranny possible. If I floor the car and let off before it switches gears the car decelerates pretty hard. This only happens in the "D4" on the car and "D3" is fine. Any idea if this is the tranny, as i've heard the early 2000 V6's had some shitty trannies. Somebody also said it could be a clogged Cat. Converter. ?