I have a P1196 that will pop up and not complete the catalyst portion of the computer. I have checked both rear o2 sensors and they appear to be working correctly, I swapped them out from right to left and reset the code but I still get a P1196. I have pinned out the complete o2 harness from pin to pin and it all rings out, wiggled the connectors and they ring out perfect continuity. I have 12 volts at the heater portion of the sensor, and I have voltage at the sensor that is variable. From a cold start engine cold the truck is in open loop about a minute later it is in closed loop that seems a little odd as the engine has not reached full operating temperature. There is two temperature sensors on the intake manifold one has a 2 pin connector and the other has a 1 pin connector one is for the gauge the other is for the computer management. Not sure which of the two is for what but shouldn't the computer go from open loop to closed loop once the engine has reached operating temperature, not sure if this is related but the only code I get is a P1196 and the only info I can find is P1196 - Oxygen Sensor Heater Type 2 Low Resistance Downstream. What side is it? Has anyone come across this and what did you do to resolve it?