Gregg,

If you're replacing your O2 sensor every 25k miles, you're waisting a
lot of money!  My manual specifically says that the light comes on after
60k miles (mine is an 87, so maybe yours comes on more often). 
Furthermore, it gives absolutely no indication as to 'how good' the
sensor is, it is nothing more than a mileage counter.  Depending on
engine conditions, it can last much longer, or much shorter.  The lights
main purpose is to remind you to 'check' the sensor, not replace it.

Tonya
87 Vanagon GL Wolfs
74 S. Beetle
Gcarlen@aol.com wrote:
> 
> In a message dated 97-04-15 05:31:08 EDT, PKirsch461@aol.com writes:
> 
> > The O2 light came on on my 85 van last week. It has 150K on it.
> >  How do I shut this off?  At what milestone was this supposed to come on?
> >
> 
> Paul,
> 
> The O2 light comes on every 25k.  It indicates that its time to replace your
> O2 sensor.  Change the sensor and then reset the light.  The reset switch is
> on a small (3-4") located under the steering column area inline of the
> odometer cable.
> 
> Gregg Carlen
> 85 Westy (144k)
> 76 Goldwing
> 51 Plymouth
> 75 Mercedes
> 69 Alcort
> ..need more toys!