First I would look at who built the motor. The 2.3 is on it's second go around. What happend the first time in less than 20k? Do a compression test, leak down, all that jazz. Stock Trans? Has the Transfer Case been gone through? Moot point, who did the tune? Is the ECU locked? If it is, will the tuner want an arm and a leg if you decide to make changes, and have someone else do it? Did he do the work, or a "buddy". Is the wiring haggard from repeated disassemblies, or neat and tidy?
Not that I've been burned on a few Mitsu's, but these are the immediate things.