What are the common causes of P04FF?

A bank 2 catalyst heater that does not reach the expected current. A failing bank 2 catalyst heater element. High resistance in the bank 2 heater wiring. A faulty ECM heater driver.

Command the bank 2 heater on and watch the heater current. Measure the bank 2 heater circuit resistance. Inspect the bank 2 heater wiring for high resistance. Replace the bank 2 catalyst if the heater current stays low. Clear the code and retest.

P04FF

Catalyst Heater Circuit Performance Bank 2

System: Auxiliary emission controls (P code)
Lamp: Check Engine Light
Category: Powertrain - Auxiliary Emissions Controls

What it means

P04FF means Catalyst Heater Circuit Performance Bank 2.

Check these first

A bank 2 catalyst heater that does not reach the expected current
A failing bank 2 catalyst heater element
High resistance in the bank 2 heater wiring
A faulty ECM heater driver

What to do next

Command the bank 2 heater on and watch the heater current
Measure the bank 2 heater circuit resistance
Inspect the bank 2 heater wiring for high resistance
Replace the bank 2 catalyst if the heater current stays low
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.