Engine light code PO141. Replaced O2 sensor (Bank 1 Sensor 2), light came back.

I used a Bosch 12108 as a replacement. When it didn't solve the problem, I exchanged it for another one at Autozone. The battery is new, but I'll test it. All wiring, fuses & relays have been checked. I don't know about the B1S2 heater circuit. I'll do some research on that. While researching OB-II Codes for PO141, one reference said it could be the catalytic convertor sensor. However, that is bank 1 sensor 3 and the read out I get is definitley bank 1 sensor 2. Thanx

Bosch O2 sensors are trash. Use ONLY Denso O2 sensors.

Yes, I replaced the one directly upstream from the sensor on the converter. Also, gas mileage does not seem to be effected by this condition. It still gets 35-37 mpg.

there are only two sensors on this car, one on the exhaust manifold(b1S1) & one after the catalytic converter(B1S2). B1S2 is down stream of the cat (between the cat & muffler). this sensor should have 4 wires. the sensor on the exhaust manifold (B1S1) has two wires.

There are four oxygen sensors, not two. Heated Oxygen Sensor Bank 1 Sensor 1, Bank 2 Sensor 1, Bank 1 Sensor 2, Catalyst Monitor Bank 1 Sensor 3. The error code says B1S2.

I have the same problem on corolla 97 can you help me?