Passenger side? If yes, I'd guess the bushing. However, it could also be that the only part of the inner tie rod that is worn is the top and bottom of the ball, which would also give up and down play without side to side/in and out play. Turn your wheel all the way to the left, which will extend the rack "bar" all the way to the right. Then grab the boot on the inner tie rod, and feel for the rack bar just to the inside of the inner tie rod. Hold the bar snug, with 1/2 your hand around the bar, and the other 1/2 around the rack housing. /Now move it up and down and you'll be able to feel if the rack bar is moving inside the rack housing.
Is the whole rack assembly moving? Are the rack mounting bolts loose? If they're tight and both ends of the rack bar are moving, you've got some serious issues. If it's just the tie rods that are moving,then you have your answer right there: both tie rods need replaced.
Comments
My Chiltons and Shop Manual both say "Tighten the tie rod securely, then bend the lock washer back onto the flange"
Found something online for who know what kind of honda 40 ft-lbs tighten rack end.
http://img84.imageshack.us/img84/8342/picture0508ev1.jpg
But who knows?