If I buy a greddy evo2 axleback for my 99 ex coupe will the sound be any different then having a catback?

 

Is it the axle-back section from a Greddy cat-back or strictly an axle-back exhaust made to work with stock piping?

 

yes

 

Yes, stock-piping to an aftermarket axleback will not sound like have a full catback system. It will be higher pitched and raspier. Not worth it IMHO. If you really want, you can have a mid-section made at any muffler shop with larger piping.