Just curious to what others are seeing. I've seen a few logs from Datalogit and most people seem to be in the high 13's low 14's with battery volts, but I'm only seeing 13.6-13.8. And I know I'm running rich but at WOT I am consistently seeing O2 Volts in the high .9's and even 1.0 and higher in a few places. I didn't even know O2 Volts higher than 1.0 were possible.

 

O2 is going bad. mine would go up to 1.17 sometimes. Get the car up to temp, a few boost runs after that and the O2 should also be up to temp. Go 55, put it in 3rd, while watching the O2 voltage and accelerated somewhat and then let off completely and see what the lowest voltage it shows. It should be .00 since no fuel is being injected in decel mod, inj duty cycles are zero as well. When mine was 1.17, the lowest I'd get would be .15 to .19, so I replaced it and its all good now, .00 and nothing higher then .93 or so.

Tim

 

Your right, I just checked my Datalogit runs and when the Duty Cycle is at 0% the O2 voltage is at 0.12. Very strange considering this sensor is less than 10K miles old. Sucks too since I can only use an OEM sensor, the bung on my downpipe is positioned so that the larger Bosch and other aftermarket sensors won't fit, they hit the fender. I guess it's another $200 down the drain at the Mazda dealer.