The light is set to come on at a certain mileage. There is a module that needs to be reset or replaced in order to shut that light off. Its just a reminder telling you its time to replace some of your emissions components such as the o2 sensor. The cheapest solution is to just pull the bulb and replace the o2 sensor when you see fit. If you take it to the dealer they may be able to reset the module, but according to my service manual the module needs to be replaced and it will just light the bulb up again at some set mileage. So unless you want a hefty bill from the dealer I'd just take out the bulb.
1992 YJ, 2.5L 4-banger, 2" Lift, 31x10.5 BFG Mud Terrain, K&N Filter, Restrictor Removed, Hi-Lift, Custom bumpers, More to come...