Ive got a 96, 3.4, 4x4 here with some troubles.
I seem to be getting three codes
PO125- Isufficiant temp for closed loop
PO133- Signal slow B1-S1
PO135- Heater circuit B1-S1
Now, the voltage to the sensor is within the perameters in all driving conditions, the fuel trim seems to be reacting ok, and it seems to have no trouble getting into Closed loop, but the sensor does not cycle between rich and lean. In most driving conditions it will be at 0/s but the odd time it will hover around 0.5/s and sometimes (usually while coming to a stop) it will spike to 16.xx/s.
Both sensors have been replaced with Bosch units with no change, i still get the same three codes, have there been any issues with these in the past? Has anyone run into this problem before that can shed some light on it?