OBD Guide

P04F8

Catalyst Heater Circuit Intermittent Bank 1

P04F8 is an OBD-II diagnostic trouble code meaning: Catalyst Heater Circuit Intermittent Bank 1. Common causes: damaged catalytic converter heater, open or short circuit in wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Check Engine light comes on
  • Reduced catalytic converter efficiency
  • Possible increase in fuel consumption
  • Unstable engine operation at idle

Causes

  • Damaged catalytic converter heater
  • Open or short circuit in wiring harness
  • Faulty heater circuit relay or fuse
  • Poor contacts in circuit connectors

How to Fix

  1. Check the condition of the heater circuit fuses and relays
  2. Inspect the wiring harness for damage
  3. Check connectors for oxidation and poor contact
  4. Check the resistance of the catalytic converter heater
  5. If necessary, replace the heater or damaged circuit elements

Related codes

Error P04F8 by Vehicle Brand

FAQ

What does the P04F8 code mean?

P04F8 is an OBD-II diagnostic trouble code that indicates: Catalyst Heater Circuit Intermittent Bank 1

What causes a P04F8 error code?

The most common causes of P04F8 include: Damaged catalytic converter heater; Open or short circuit in wiring harness; Faulty heater circuit relay or fuse; Poor contacts in circuit connectors.

How do I fix a P04F8 diagnostic trouble code?

To fix P04F8: Check the condition of the heater circuit fuses and relays. Inspect the wiring harness for damage. Check connectors for oxidation and poor contact. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P04F8?

Limited driving only, diagnose soon

How much does it cost to fix P04F8?

The estimated repair cost for P04F8 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat