O2 sensor resistance?

Question

Recently replaced head gasket and valve job. Now have P0134 check engine. Have 3 O2 sensors for spares. The resistance is maybe 0.1 ohm difference and the OB2 live data shows fuel sys1 OL fault as soon as the check engine light resets. All 3 O2 sensors have he same reaction and throw the same code. One sensor is Bosh, one is Denso, and the other is NGK. Other than the timing being a little up and down, she runs great. No smoke but spark advance jumps from 6 to 10 and every where in between. What should the resistance of the O2 sensor be?