WBO2 question NTK box

[Carl Summers]

Hi all,
     What exactly is an O2 sensor and how does it work??? JUST KIDDING!!!!
:)
Have any of you experienced one of these boxes "falling" out of
calibration???? I was tuning an efi on the dyno Friday and all of a sudden I
started getting erratic AFR's...was datalogging all of the essentials and
had nothing else varying (EGT's, Fuel pressure, HP, etc).  I assumed the
failure of the sensor since I had logged over 50 hrs on it so I installed a
new one to no avail....AFR would be 12.7:1 on one pass and 14:1 on the
next...same 1250 egt and same hp....what gives??? I double checked my pw to
make sure I hadn't lost stability and at max rpm was 82% so I can't see it
there....datalogged battery voltage as well as engine temp also no changes
or weird stuff....anybody had this happen before???? I didn't have my other
box with me so I was lucky that I was done with the calibration and was just
making these last pulls at very long sweeps(100 rpm every 10 seconds) to
verify timing curve (no Knock). This was a NA 540 8.8:1 Aluminum head 625hp
630tq....nice thing about efi, torque was 600+ from 3000-5500rpm. Thanks,
clues or feedback needed....ttyl
-Carl Summers

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