P04F3
Catalyst Heater Supply Voltage Bank 2
Generic OBD-II
Common symptoms
What you'll notice
- Check the wiring and connections of the catalyst heater in bank 2
- Test and replace the catalyst heater in bank 2 if necessary
- Inspect and replace any faulty fuses related to the catalyst heater in bank 2
- Reset the OBD 2 error code and monitor if it reoccurs
Common causes
Most likely first
- Faulty oxygen sensor in Bank 2
- Malfunctioning catalytic converter in Bank 2
- Issues with the wiring or connectors related to the catalyst heater in Bank 2
- Engine control module (ECM) malfunction related to catalyst heater in Bank 2
- Faulty airflow sensor or fuel injector in Bank 2
How to diagnose & fix
Work through it in order
- Check engine light illuminates on the dashboard
- Engine misfires or runs rough
- Decreased engine performance or power
- Increased fuel consumption
- Poor vehicle acceleration or sluggishness
Read & clear P04F3 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.