Recently I have been down on power at the track so I did some logging and found that my B2S1 readings were on average 100mV more than B1.
After I got home and the car sat for a couple of days I connected to the pcm with Hp Tuners proir to starting the car and noticed the B2S1 reading would not fall down as low as B1, it ran about 70mV higher. Once I started the car all hell broke loose. B1 readings settled in at an average of 170 mV with a straight line on the graph but B2's readigns were all over the map ranging from 300 to 900 mV with the graph looking like a zig zag.
So is the B2 O2 no good? I checked all the header bolts to be sure nothing was loose causing an exhaust leak. Is there a way to test the O2 off the car with a multimeter?
Also are the B2S1 and B2S2 O2s the same? Both of them have the same PN on them AC AFS-97 so could I put an old B2S2 sensor I have in the S1 location?
Also I have a short log file from HPT if someone wants to look at it.

 

Messed up O2 sensors will have NO affect on performance at the track because they arent even used during WOT operation. During WOT PE the PCm relys strictly on the MAF and PE tables to calculate fueling.
Sounds like you B1 might be dead. The signal of an O2 sensor should be up then down, up, down continuosly. Your B1 has the flatline which is bad. The front and back sensors are the same too so yes you can swap them.

 

Thanks. I actually just figured out that it must be my B1 sensor that is bad becasue I swapped the B2S1 sensor with a new one then logged again and it read the same. I am now going to take the O2 I just removed and replace it with the bad B1S1 O2.
Also if O2s do not control WOT what else can cause me to lose top end power and run so fat I started blowing black smoke?

 

By swapping around O2's to eliminate the bad B1S1 O2 I have fixed the problem (although I didn't know it was the problem..oh well live and learn).
The biatch was that although I had an extra good B2 O2 the wire was not long enough for the pre cat position. I had to take the after cat o2 and put it up front then take the old B2 O2 and put it in the after cat bung and the wire there was just barely long enough but it worked and I'm happy.
Will a pcm relearn help now?
Now I need to look at my WOT rich condition

 

If your MAf table is set too high it will cause you to be rich at WOT. Start with basic tune up and a reset of the PCM and go from there. Monitor the signal from the o2 sensors to make sure they are switching right and are reading the proper values to keep AFR at 14.7 during closed loop.