The O2 sensor light came on in my Trooper. The light is on at all times but I notice no difference in performance, mileage, idle, etc. Do I need to buy a new sensor, and does the panel light have to be reset by a mechanic?

I'm kind of "old school" here; anything without a point-type ignition and carburetion is "new fangled" to me.

Thanks in advance,

Tato

1993 Trooper
"Purple People Eater"