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View Full Version : Pre and post cat O2 sensor



grayscale
05-14-2007, 03:26 PM
What is the difference between the two?

evolution
05-14-2007, 03:33 PM
as i understand it, the first one is used to tune the a/f mixture, and the one after the cat is used to check the efficiency of the cat

grayscale
05-14-2007, 03:43 PM
So does this mean they won't provide the same info to the ecu if they switched places? I wonder if I could use a 3sfe sensor? 90-91 Celica has different pn#, is it just because the connector is different or is the sensor different?

DarkSideCelica
05-14-2007, 07:17 PM
all sensors are the same.. only difference is the connector and wire length

grayscale
05-14-2007, 07:39 PM
Perfect answer, thanks DSC!

Rix86
05-16-2007, 03:03 AM
not true.
not all sensors are the same.
they might be on that year celica, but i doubt that even.

DarkSideCelica
05-16-2007, 06:14 PM
not true.
not all sensors are the same.
they might be on that year celica, but i doubt that even.

i sell them, so i'm pretty sure they're the same for a specific application... :)

of course there are variances for different makes and model like the number of wires the sensor uses, wire length and connector