Addco sway bars, front and rear are I believe the preferred mod to fix this. Not sure about the front but the rear upgrades from 9/16" diameter to 1", correcting a lot of understeer on the vehicle.
You may want to check to make sure the bar is still properly bolted in and the end links are not broken, this could be a problem if the understeer is extensive.
This is a fairly easy upgrade to do, unbolt the old bar and bushings, and install the new bar and bushings. I haven't done this one yet but its on my list.
My Jeep: 2001 Grand Cherokee Limited, 245/65R17 Falken Rocky Mountain ATS, K&N drop in air filter, Bilstein HD's. De-badged, eagle-eye LED Tails & LED 3rd brake light, Addco front and rear sway bars, Superchips tuned & TM snip, interior 6k LED's, Gen3 ccfl projectors with Volt 6k HID lows, akebono brake upgrade with R1 Concepts premium rotors.