Bouncing O2 Voltage

[69_luv]

My logger said 0 for O2 Voltage so I threw a new O2 sensor in, now my readings jump from .14 to .90 back and forth all over the place. Any ideas? Could the rear O2 sensor be causing this? I only replaced my upper.

Thanks for any help

 

[dthquazi1]

thats how its supposed to be. At idle it goes into open loop. It cycles through the o2 range. It closes when you ope the trottle.

 

[69_luv]

when I start the car it slowly climbs, and then once I give it gas it goes crazy. When I did a 2nd gear, and 3rd gear pull my logger said like
5850rpms and .98o2
5960rpms and .14o2
6150rpms anb .87o2

some crazy stuff like that. Your saying thats normal?

 

[Syndicate13]

Are these readings at WOT? At idle and cruise the O2 voltage should go back and forth from .2-.8 roughly. Up and down, up and down. This is the ECU trying to establish that perfect air/fuel ratio of 14.7:1. When at WOT the ECU quits looking at the O2 voltage and adjusts fuel according to it's own little fuel tables. At WOT the voltage should be no lower than .92 if you're running 93 octane pump. Depending on how rich your car is and boost leaks your voltage could be as high as 1.xx, I've seen mine there a time or two when I had some nasty leaks.