P019A
O2 Sensor Delayed Response Rich to Lean Bank 1 Sensor 3
Generic OBD-II
Common symptoms
What you'll notice
- Check the wiring and connections of Bank 1 Sensor 3 O2 sensor
- Test and replace the Bank 1 Sensor 3 O2 sensor if faulty
- Inspect and clean the mass air flow (MAF) sensor
- Check for any exhaust leaks or damaged catalytic converter
Common causes
Most likely first
- Faulty or failing oxygen sensor in Bank 1 Sensor 3
- Vacuum leak in the exhaust system
- Fuel pressure regulator malfunction
- Issues with the Engine Control Module (ECM) or sensor wiring
- Exhaust system leaks or damage
How to diagnose & fix
Work through it in order
- Decreased fuel efficiency
- Rough idle or engine misfires
- Difficulty starting the vehicle
- Increase in emissions/smoke from the exhaust
- Loss of power or acceleration
Read & clear P019A yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.