P0141 — O2 Sensor Heater Circuit (Bank 1 Sensor 2)

What it means

The heater element of the downstream oxygen sensor on bank 1 draws a current outside the specified range, so the ECM reports an open, short or excessive resistance. Because this sensor sits after the catalytic converter where exhaust gas is already cooler, it depends heavily on its heater to reach the roughly 300 degrees Celsius needed for a stable signal. Without it the catalyst efficiency monitor cannot run, the readiness flag stays incomplete and the MIL comes on, although engine performance itself remains normal.

Likely causes (most common first)

1. Open or shorted heating element inside the downstream oxygen sensor
2. Blown fuse in the sensor heater supply circuit
3. Corroded underbody connector or wiring damaged by road debris and salt
4. Poor ground connection causing an excessive voltage drop
5. Faulty heater control output in the engine control module
6. Aftermarket sensor with the wrong heater resistance

Can you drive with it?

The fault does not affect performance, so you can drive normally and replace the sensor at your convenience.