30,000 miles on early models.
60,000 miles on '86 and newer. Possibly even back to 83.5 year models.
To reset, just use a stubby phillips screwdriver  and depress the button
in the little detent on top of the box mounted above the spare tire. The
cable from the  left wheel feeds into the box, and from there a second
cable goes to the speedometer. The little box is just a counter that
counts to the next 60,000 miles from the last reset, then turns on the
light.

The O2 sensor light in the odometer is in no way connected to the O2
sensor itself. For that reason, you can choose to simply reset the thing
when it turns on, yet still drive around with your old O2 sensor. Not a
good idea, but it can be done. One has nothing to do with the other
except act as a warning of need for replacement.

Regards,

John Rodgers
88 GL Driver

Ed Lloyd wrote:
> I too had a broken odometer for a couple years.  I finally fixed it thanks to the List.  Took two tries, but works now.
>
> Lost a couple years of odometer reading and don't know what it should be now.
>
> Then, the Oxygen Sensor light came on.  I replaced the sensor, but the light stayed on.  I have learned that it has a re-set button on the speedometer cable, and it lights up at 50,000 or perhaps 60,000 miles.
>
> Does anyone know the exact light up mileage?
>
> I can then calculate my lost miles by subtracting the odometer from the 50,000 or 60,000 oxy miles.
>
> Will this work?
>
> Ed in Rockville, Md
>
>
>