thats your problem right there the stock accord PCM has the TCM built in thats why theres 4 plugs were as the prelude ECU the TCM is a seperate unit in the 97 + USDM and most JDM ones as well so if you pluged your Dx PCM in it work and shift but no vtec as with the prelude ECU the car will only drive in 1st and reverse unless you shift it.