P0138 means the Bank 1 Sensor 2 oxygen-sensor circuit has reported a voltage that is higher than expected. The downstream sensor, wiring, connector, or an exhaust or fuel condition may be involved; ...

P0141 stands for Oxygen Sensor Heater Circuit Malfunction on Bank 1, Sensor 2. It shows that the onboard heater circuit isn’t operating normally on the downstream oxygen sensor from bank 1. With a ...