Common issues I believe are the standard "subaru deceleration noise" and also clutch chatter. I think I've read on here that 02-03's are notorious for clutch chatter, and that it can be made worse with different flywheels and maybe clutches. Mine makes an aweful scraping noise when I let off the gas all the way down between 3000->2200. Goes away when gas is given or when clutch is pressed or in neutral. But it will happen any time I take my foot off if the engine is between 2200-3000rpm. I've just grown to live with it for now as I think its ok and not doing any terrible harm. You can try searching on here for the decel noise and search out threads with tire pressures in them. Supposedly you can lower your rear tire pressure a few psi lower then the fronts I think and it helps lower the noise...but do a little snooping and see what you come up with.