i've got a '92 pathfinder with 200k miles on it and have never had a single problem with the engine. the transmission was replaced several years ago, maybe around 150k miles. it had some minor frame rusting that cost about $400 to have fixed and re-welded just to be safe, this was about 2 years ago. not too bad considering its age and the wonderfull PA winters and all the road salt penndot loves to lay down. there's also some rusting where the running boards used to be... they rusted off, heh. a few minor electrical issues (cd player went bad, put in a cheapo aftermarket one that plays mp3's now), and the rear brakes have been an issue the last 2 years.
considering how old it is and what its been through, i'd say it's been a champ. the maintanence costs have been reasonable, and its a beast in the snow. i'm not sure how this helps you with an '01, heh, but i thought i'd share my experience.