Stay away from the 02 if you plan on modding it as the transmissions are weak. Some 03 models have beefed up gearsets as they changed partway through the model year, but make sure to check if the car you're buying has them.

All 02-04s are 2.0L and there are lots of mods available. All subaru 5 spds are somewhat fragile so take that into consideration. When I say somewhat fragile I mean don't launch it, and 300-350whp may be too much for it. If you mod lightly (downpipe, tune, ic, etc) and don't drive like an idiot you'll generally be fine in an 04. If the car shows signs of being driven hard don't buy it as it'll give you trouble (transmission grinds or doesn't want to go into gear normally...car hops or binds around tight corners. Reverse is always hard in a subie...so disregard that.).

Also, these cars go through tires faster than normal...just fyi. Also, if you bust one tire after more than 10,000 miles you'll have to replace all 4 to avoid screwing up your differentials as tire diameters must all be within a certain tolerance.

Also, don't put an aftermarket BOV on them. it's terrible for the car unless you tune for it.

PM me if you have any other questions. GL!