P0157
O2 Sensor Circuit Low Voltage Bank 2 Sensor 2
What it means
P0157 means O2 Sensor Circuit Low Voltage Bank 2 Sensor 2.
Where it lives
For P0157, the sensor sits on the circuit this code reports. The description of P0157 puts it on bank 2.
Check these first
- A short to ground on the bank 2 sensor 2 signal wire
- A failed downstream oxygen sensor on bank 2
- An exhaust leak making the sensor read lean
- Resistance in the bank 2 sensor 2 wiring
- A contaminated oxygen sensor
What to do next
- Inspect the bank 2 sensor 2 wiring for a short to ground
- Check for an exhaust leak near sensor 2
- Test the sensor 2 signal voltage
- Replace bank 2 sensor 2
- Verify the ECM if the reading stays low
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.