02 sensor problem p0134

Grand am 3.1 96 with p0134, tested all wires for continuity to pcm all were good, replaced 02 sensor 1 and still the same problem. I also noticed that o2 sensor 2 does not have any activity at all it is stuck to 4mV however o2s1 is showing some signs of life moves from 434mv to max 459mv. Did anyone have this problem before please help.

did you test these when they were hot ?

They should show a better reading when up to temprature.
Check the wiring for the O2 down stream and its plug, it should be reading something. This O2 might be bad as well if thiers no activity.

Thank you XI this one is solved. It was a loose female connector for the O2 sensor (pcm side).