P0145 Code: O2 Sensor Circuit Slow Response Bank 1 Sensor 3
🟠 Moderate severity · drivable
You can drive, but the engine may use more fuel and may fail an emissions test until the sensor is replaced.
What P0145 means
The bank 1 sensor 3 oxygen sensor responds too slowly to changes in the exhaust. The sensor is getting old or contaminated and cannot switch fast enough. The computer notices the lazy response and sets this code.
Symptoms
- Check engine light on
- Poor fuel economy
- Rough running
- Failed emissions test
Common causes
- most common: Aged or worn O2 sensor
- common: Contaminated sensor from oil or coolant
- less common: Wiring or connector issues
- less common: Exhaust leak
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the O2 sensor | Yes | $80–200 |
| Fix the contamination source and replace the sensor | Mechanic | $150–500 |
| Repair the wiring or connector | Yes | $20–80 |
| Fix the exhaust leak | Mechanic | $50–300 |
Frequently asked questions
Can I drive with P0145?
Yes, but the engine may use more fuel and may fail an emissions test until the sensor is replaced.
What does slow response mean?
The sensor still works but reacts slowly to exhaust changes, usually because it is old or contaminated.
How often do O2 sensors need replacing?
Many last 60,000 to 100,000 miles, but contamination and age can wear them out sooner.
Related codes
P0142
P0142 Code: O2 Sensor Circuit Bank 1 Sensor 3
P0143P0143 Code: O2 Sensor Circuit Low Voltage Bank 1 Sensor 3
P0144P0144 Code: O2 Sensor Circuit High Voltage Bank 1 Sensor 3
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.