What causes P1304 on a Honda?

Worn spark plug or weak coil on cylinder 4 Restricted or dirty cylinder 4 fuel injector Intake leak at the cylinder 4 runner Worn rings or valves lowering cylinder 4 compression Faulty spark voltage detection module

How do I fix P1304 on a Honda?

Confirm the code and check for other misfire codes Inspect the spark plug and coil for cylinder 4 Test the cylinder 4 injector and check fuel pressure Check vacuum leaks and compression on cylinder 4 Repair the cause found Clear the code and retest

P1304 The powertrain control module saw misfire in cylinder 4

Q: What does P1304 mean on a Honda?

P1304. The powertrain control module saw misfire in cylinder 4. The engine may run rough, shake at idle, or lose power.. Applies to Honda and Acura models that use this code.

Category: Powertrain - Ignition
Severity: Check Engine Light
Applies to: Honda and Acura models that use this code

This fault is part of the Honda misfire codes guide. It covers the system and the order to check it.

What does P1304 mean on a Honda?

P1304. The powertrain control module saw misfire in cylinder 4. The engine may run rough, shake at idle, or lose power.. This Honda-enhanced code applies to Honda and Acura models that use this code.

Common causes of P1304

Worn spark plug or weak coil on cylinder 4
Restricted or dirty cylinder 4 fuel injector
Intake leak at the cylinder 4 runner
Worn rings or valves lowering cylinder 4 compression
Faulty spark voltage detection module

How to fix P1304

Confirm the code and check for other misfire codes
Inspect the spark plug and coil for cylinder 4
Test the cylinder 4 injector and check fuel pressure
Check vacuum leaks and compression on cylinder 4
Repair the cause found
Clear the code and retest

Sources and review

Checked against two independent sources.
Last updated 2026-10-10.