Known good O2 sensor giving bad readings

[GNandTTA]

Having a problem with the GN's O2 readings. I can take the good O2 out of the TTA and put it in the GN and the O2 reading hover right around 400 - 500. That same O2 in the TTA gets reading anywhere from 100 - 800. Both are showing good cross counts on Turbolink. Anyone have any idea what could be causing this. Car stays in open loop much longer than the TTA. It has drivability problems as well. Figured this is the first place to start.

 

[TurboDave]

Can you tell us what chip you have in your GN?
Any other data that you think might help get to the bottom of this.

 

[GNandTTA]

It is a Kenne Bell chip that I've used since 1989. Car used to run good with this chip. Swapped ECM's with the TTA and this did not help either. This car now has the cam sensor that I "fixed". This was the TTA's problem all along. It had a lot of play up and down (almost "1/4") and I very recently added a few shims (washers) to it. It appears to be back to the way it should. It has roughly the same up and down play as a good sensor. Phisically it looks the same as the one that is now in the TTA. Kind of scared to pull the one out of the TTA since the car is running so good right now. I think for peace of mind I will just get a new GM one. But if anyone has any ideas please let me know.