P04F6

Catalyst Heater Circuit High Bank 1

Moderate severity

Same as P04F4 with the line shorted to supply or open - the ECU measures higher voltage than the commanded duty cycle allows.

Common causes

Control line shorted to supply
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $330-2420
Open in heater element or harness
A plausible cause — test and verify before replacing parts.
medium
Typical part cost: $330-2420
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does P04F6 mean?

P04F6 means "Catalyst Heater Circuit High Bank 1". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P04F6?

control line shorted to supply; open in heater element or harness; connector pins corroded - high contact resistance — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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