yes as far as I know they are but there are different size ram in some ps 2 3 volt boards so as long as the ram is enough for your sound file they will work. ps 3 the diesel boards are totally different then steam. the largest ram on p s 2 is 2 meg max, if I remember correctly. if the ram is made by SHARP as marked on top the ic it is 2 meg. you just have to use the dcs loader program and install the correct sound file for the engine you need
if you give me the item number ill put the sound file on here for you!
ps you can just swap the black and white connectors on the boards will work the same type just fit the harness a little different you can heat them if your careful to soften the connector so they will come off easier, or if you know how and can be careful very careful a knife edge will pry them up. if you use a heat gun just don't heat the electronics only the soft white or black connectors, I have done it many times!l
email me here is the sound file