Oxygen sensors plugged in, brand new Fbody, brand new DBC harness from PSI in NJ, no extensions, heater circuit has power and ground, sensor gets hot key on engine off, purple and tan wires are in 26/66 and 29/69 like they are supposed to be and continuity test checks out, but always reads stagnant 447-449 mV.
I can use open loop target A/F to drive the car stumbling rich to misfiring lean and the voltage readings dont change. How is the PCM no seeing a different voltage?
Also even up to 180F running the closed loop status bit never changes when the Closed Loop Enable is at 100 or so degrees?
Found customer had one of the cylinder head grounds not on at first, but still acts the same after finding that