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Old 11-17-2008, 04:21 AM   #7 (permalink)
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uberhho -

Originally Posted by uberhho View Post
I have heard that if one has two oxy. sensors that the single efie should be connected post-cat. Having two means that there is a reading before and after the catlist has done its job. I'm not quite sure why there would be two. Maybe it is to improve emisons. I'm working on a DUAL EFIE with higher grade conponents that are more sound under your bonet.
I agree that having an EFIE for every 02 sensor would make the behavior more "normal". I definitely think the second 02 measures the efficiency of the cat *and* the health of the cat (I think they are the same thing). Because of the cat-health issue, I am leery of installing a second EFIE.

I don't think that a single EFIE configuration should be connected to the second 02 sensor because I can *see* the 14.7 ratio with the digital A/F gauge. The second 02 sensor is operating in a different range because I can compare readings when I datalog :

Also, it goes against the logic of what I have read regarding closed-loop operation. What I have read tells me that the *first* 02 sensor is used to determine fuel injection at the stoichiometric ratio of 14.7 to 1.


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