P0144
O2 Sensor Circuit High Voltage Bank 1 Sensor 3
Emissions / oxygen sensor
Generic OBD-II
Medium
What it means
P0144 means the oxygen sensor on bank 1 in the third (deep downstream) position is reporting a voltage that's higher than the ECM expects, usually because of a short to voltage, a wiring fault, or a failing sensor. This sensor mainly monitors catalyst and emissions performance, so the engine typically drives normally — but the code must be fixed to clear the light and pass emissions testing.
Medium
Can I keep driving? Safe to drive — this is a downstream oxygen-sensor circuit fault; the engine runs normally, but emissions monitoring is affected and it won't pass a smog test.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- Possible slight loss of fuel economy
- Increased emissions / failed readiness monitor
Common causes
Most likely first
- Faulty bank 1 sensor 3 oxygen sensorLikely
- Signal wire shorted to voltage or a short between wiresCommon
- Corroded or loose connector at the sensorCommon
- Exhaust leak near the sensor skewing its readingLess often
- Faulty ECM/PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and view the live bank 1 sensor 3 voltage — a stuck-high reading points to the circuit or sensor.
- Inspect the sensor connector and wiring for a short to voltage, chafing, or corrosion.
- Check for exhaust leaks upstream of the sensor.
- Compare the sensor's behavior with a scan tool; replace it if it stays pegged high.
- Clear the code and drive a full cycle to confirm the monitor completes.
FAQ
Quick answers
Is it safe to drive with P0144?+
Yes. A downstream (post-catalyst) oxygen sensor mainly monitors emissions, so the car drives normally. Repair it to clear the light and pass emissions testing.
Can I just clear P0144?+
You can, but it returns if the sensor or wiring is faulty, and the emissions monitor won't stay ready. Fix the circuit first.
Related codes
Often seen with P0144
Read & clear P0144 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX