I had codes 0125, 1153, 1155, changed the front O2 sensor (underhood exhaust manifold) and the problem went away.
For me i believe the sensor was still functional, the heater malfunctioned. (both are parts of the af sensor)
when the cel was on, the car performed flawlessly. 22 mpg, normal. when i tested the old part, the heater loop was open circuit.
Maybe you have the same problem, there are many threads. Also, you can buy a OBDII tool and look at the o2 sensor values with the car running. Play detective.