Do what I did just take the bulb out. I dont have factory exhaust and it didn't effect my emission output to I just pulled the bulb problem solved!! But really if you have emission tests you might want to have it looked at
1998 Grand Cherokee 5.9 Limited Edition, Upcountry Suspension for Now, Infinity Sound, NP 242 Swap
2002 Jeep Liberty Sport 4x4 3.7L Auto
1998 TJ 4.0 Auto Sahara Package 4" Suspension Lift 33 BFG Hard & Soft Top
The maintenece required light is on a timer that tells you when your O2 sensor is due to be changed. I think the timer is set for 85000 miles The only way to shut it off is to replace the timer. Just take out the bulb and the problem is solved
Actually on a 1992 the timer light is able to be turned off, I got mine to shut off, I think by just replacing the O2 sensor. I do believe that was at 85,000 miles. For some reason mine came back on, when I was in the garage for a diagnostic check the tech just reset it with a scan tool and the thong has been off for the last 10,000 mi. I think on the older models yopu have to take the bulb out or whatever. If the light bothers you just stick some tape over it until you can figure it out or have someone reset it. I think it may say how to do this in the Haynes I will look later.
Just had mine cleared at the dealer with the DRB II - most of the time they will do this for you at no charge.
The FSM confirms that the ONLY function of the Maint Req'd light is to remind the owner to replace the O2 sensor and other components and that it is only triggered by time... for older models ('91 is when they changed it I think) the timer was semi-mechanical, for newer ones it's all electronic and based on cycles of ignition timing, so there's no set way to know how many actual miles will fire it - I've heard that lots of high revving will cause it to fire sooner.
Also, it's not indicitave of the actual state of your O2 sensor at all, it's just a 'good idea' to replace it every 80k...I've got a nice O2 sensor tester that lets me check the condition of O2 sensors...neat tool. Replacing the sensor alone will not shut off the light.
...talk about generating repeat business for the dealers...
'92 YJ Sahara / OME / BFG AT/TA - a few other rides.