have you tested the circuit for the oxygen sensor. It could be something as too much resistence in the circuit. Or the coolant temp sensor. I know you replaced the sensor, but often times the problem doesn't lie in the sensor itself. I would do a voltage drop across all the wires leading to the o2 sensor and the coolant temp sensor. If you email me i will right up how to test the sensors, but you will need a wiring diagram.
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