O2 readings jump

[madhat]

I just bought a brand new AC Delco O2 sensor and the Bosch one I had before was reading about 380-410 constantly...this "new" AC part(it had carbon on the sensor like it had been used) Doesnt jump down to 35 like my old one did, but it read from 140-700...is this a bad sensor?

 

[Tim Riecks 6]

It should jump around. If it doesn't then there would be something wrong (whether it be the sensor or otherwise).
The only time it should have a somewhat constant reading is when you are accelerating heavily.
The jumping around is where you get your cross counts (on a scan tool) from.

 

[madhat]

thanks