P0304 on FORD FUSION — Cylinder 4 Misfire Detected

Q: "What does P0304 mean on a FORD FUSION?"

"P0304 indicates: Cylinder 4 Misfire Detected. This is a ignition system code. 17 FORD FUSION owners have reported this to NHTSA."

Q: "What are the most common causes of P0304 on FORD FUSION?"

"Based on 17 NHTSA reports, the most commonly cited components are: Engine, Engine And Engine Cooling, Unknown Or Other. These percentages are based on the component field in owner complaints."

Q: "Is P0304 serious on my FORD FUSION?"

"Of 17 NHTSA reports for this code on FORD FUSION, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my FORD FUSION shows P0304?"

"1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare."

What P0304 Means on Your FORD FUSION

P0304 is a diagnostic trouble code indicating: Cylinder 4 Misfire Detected. This code relates to the ignition system system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

17 FORD FUSION owners have reported this issue to NHTSA across model years 2013-2019. Most reports come from the 2016, 2015 model years. The most commonly reported component is Engine (64.7% of reports).

Real FORD FUSION Owner Reports

Source: NHTSA Complaints Database

"Coolant leak from freeze out plug causing car to overheat first engine light flashed causing a p0304 code then smelled coolant and started overheating"

— 2013 FORD FUSION owner · ENGINE · Filed 03/09/2020

"My Ford fusion has a coolant leak and ford said I need a repair. Price for repair is $9,584.89. It is a known problem with a TSB (see below) Summary This article supersedes TSB 19-2139 to update the production fix date."

— 2015 FORD FUSION owner · UNKNOWN OR OTHER · Filed 12/14/2022

"2015 1.5L Ecoboost misfiring/running rough/coolant level low. While driving highway speeds engine began to lose power and shutter ultimately shutting down causing significant lose of braking and steering."

— 2015 FORD FUSION owner · ENGINE · Filed 04/01/2022

"Just got this ford vehicle a couple months ago and for some reason my car wouldn't start. i ran a diagnostic and had numerous codes p0300, p0301, p0302, p0303, p0304, p0030, c0014, p0047, p0141, and a few others. i looked for loose wires, checked fuses, plugs etc."

— 2015 FORD FUSION owner · ENGINE · Filed 03/17/2021

"Coolant intrusion into cylinder 1, low coolant and Engine DTC P0301. Multiple TSB's by Ford recommend engine replacement as a remedy for the Cylinder head - open deck cooling problem. Customer Satisfaction Program 21N12 addresses this problem in similar cars/engines."

— 2016 FORD FUSION owner · ENGINE · Filed 06/01/2025

All reports filed by vehicle owners directly with the U.S. Department of Transportation.

📊 Complaint Trend by Model Year

1

'13

3

'15

6

'16

3

'17

1

'18

3

'19

Common Causes on FORD FUSION

Based on NHTSA complaint component analysis for this vehicle.

ENGINE 64.7%

ENGINE and ENGINE COOLING 11.8%

UNKNOWN or OTHER 5.9%

ELECTRICAL SYSTEM,UNKNOWN or OTHER,ENGINE 5.9%

UNKNOWN or OTHER,ENGINE 5.9%

What To Do Next

1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.

Frequently Asked Questions

What does P0304 mean on a FORD FUSION? ▾

P0304 indicates: Cylinder 4 Misfire Detected. This is a ignition system code. 17 FORD FUSION owners have reported this to NHTSA.

What are the most common causes of P0304 on FORD FUSION? ▾

Based on 17 NHTSA reports, the most commonly cited components are: Engine, Engine And Engine Cooling, Unknown Or Other. These percentages are based on the component field in owner complaints.

Is P0304 serious on my FORD FUSION? ▾

Of 17 NHTSA reports for this code on FORD FUSION, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my FORD FUSION shows P0304? ▾

1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare.