P0144 Code: O2 Sensor Circuit High Voltage Bank 1 Sensor 3
🟠 Moderate severity · drivable
You can drive, but fuel economy may drop while the computer runs the mixture rich.
What P0144 means
The bank 1 sensor 3 oxygen sensor is sending a voltage that is too high and stays high. This usually means the sensor is faulty, contaminated, or the wiring is shorted to power. The computer may think the exhaust is rich.
Symptoms
- Check engine light on
- Poor fuel economy
- Engine runs rich
- Black exhaust smoke in severe cases
- Failed emissions test
Common causes
- most common: Faulty O2 sensor
- common: Wiring short to power in the sensor circuit
- common: Contaminated or poisoned sensor
- less common: Coolant or oil in the exhaust
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the O2 sensor | Yes | $80–200 |
| Repair the wiring short to power | Yes | $20–80 |
| Find and fix the contamination source | Mechanic | $100–500 |
Frequently asked questions
Can I drive with P0144?
Yes, but fuel economy may drop while the computer runs the mixture rich. Fix it soon.
What makes an O2 sensor read high voltage?
A rich exhaust, a faulty sensor, or wiring shorted to power can keep the voltage high.
Can coolant or oil ruin an O2 sensor?
Yes. Coolant or oil in the exhaust poisons the sensor and makes it read wrong, so fix the leak before replacing it.
Related codes
P0142
P0142 Code: O2 Sensor Circuit Bank 1 Sensor 3
P0143P0143 Code: O2 Sensor Circuit Low Voltage Bank 1 Sensor 3
P0138P0138 Code: O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.