John W. Wells wrote in
>news: snipped-for-privacy@4ax.com:
>
>
>>
>> From what I've been able to find out, Toyota used a (relatively
>> inexpensive) O2 sensor prior to 1991, but went to the more costly A/F
>> sensor after that (upstream from the CAT--I think the downstream one
>> may still be an O2).
>
>
>
>The secondary sensor (after the cat) is _always_ an O2 sensor.
>
>Toyota began using A/F sensors in 1997, starting with the 1997 CA-market
>4-cylinder Camry. By '02, only 4-banger Toyotas and a couple of V6's still
>used O2 sensors for the primary.
>
>A/F sensors may be across-the-board now for the primary, but I'm not sure.
And to add to my confusion, when I picked up the car yesterday, the repair shop's receipt listed them as "O2 sensors." And both of the old parts are identical (Denso, Toyota OEM). The counter man said that A/F, O2, whatever--they're all called O2 sensors now! Wunnerful!
Thanks for your reply!
--John W. Wells