Your stoich changes all the time, thus the correction factor they apply to go from lambda (which is what these sensors read) to AFR, will almost always be wrong.
Likely you have a bad controller or wiring.
That sensor was the same one they used in the NTK AFX for the longest time. Only difference was the controller.
Ok. Thanks. I will check out the harness when I get time to jack the car up. I have it in gas mode never bothered changing it. Just calibrated it. Thanks for all the help.