Re: OXS light

[zm@mhcnet.att.com (Zafer Mehmood [209])]

Graydon D. Stuckey wrote:
> 
> 	I replaced the oxygen sensor on my father's 5KTQ a year ago.  It 
> had alot of miles on it, and when I installed the Air/Fuel ratio meter, I 
> noticed that the sensor was not giving a signal that made any sense, even 
> though the OXS light had not lit up.  After I replaced it, everything 
> was back to normal, and Dad typically gets 30-35mpg now.
> 	Note that Bosch O2 sensors are only expected to last 60,000 
> miles, although I have seen them last alot longer than that.
> 	If your OXS light has lit, that probably means you need a new 
> one.  I would recommend replacing it.  They are not very 
> expensive.
> 

I have a few questions on O2 sensors:

1. Do the 5KTQ's have an OXS warning light? I don't see it on my car
   (87 5KTQ) or in the owner's manual.
2. What's the typical gas mileage for the stock 5KTQ? I get anywhere
   from 21 (city) to 25 (highway) in my car (the trip meter shows 10% more
   though). Is this low? I can't imagine getting 30-35 on my 5KTQ. May
   be my O2 sensor needs replacement (135K on the original sensor)? No
   drivability problems, no computer error codes set, and the car has
   passed emissions in the past. I would consider replacing it if I get
   improved mileage.
3. How much does the O2 sensor cost? Any suggested parts vendor?

TIA.

Zafer