P04F6
Catalyst Heater Circuit High Bank 1
Generic OBD-II
Common symptoms
What you'll notice
- Inspect and replace the oxygen sensor in Bank 1
- Check and repair any wiring issues or damage in the catalyst heater circuit
- Clean or replace the catalytic converter in Bank 1
- Verify and repair any issues with the engine control module (ECM) related to the catalyst heater circuit
- Replace the catalytic converter in Bank 1
Common causes
Most likely first
- Faulty oxygen sensor
- Malfunctioning catalytic converter
- Engine misfire
- Vacuum leak
- Faulty fuel injector
How to diagnose & fix
Work through it in order
- Check engine light on
- Decreased fuel efficiency
- Rough or irregular engine idle
- Difficulty starting the engine
- Reduced engine performance
Read & clear P04F6 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.