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P0304 on FORD MUSTANG

Severity
Medium
NHTSA Reports
2
Most Affected
2019

What P0304 Means on Your FORD MUSTANG

Real FORD MUSTANG Owner Reports (Source: NHTSA Complaints Database)

"Have a 2019 Ford Mustang 2DR 2.3L Ecoboost with 59,500 miles which I took to the dealership with a code P0302 and P0304 present, cylinder misfire, observed coolant level low, performed borescope in cylinder 2 and 4, found coolant intrusion, recommend long block engine replacement which would have co"

— 2019 FORD MUSTANG owner • ENGINE • Filed 12/02/2025

"On Repair Order #:[XXX] at Lorenzo Ford, the dealership technician documented the following: “Verified customer concern, DTC P0304 perform pinpoint test, inconclusive, perform coolant pressure test and found coolant intrusion into cylinder 4."

— 2019 FORD MUSTANG owner • ENGINE • Filed 08/04/2025

Data from NHTSA Vehicle Complaints Database. All reports are filed by vehicle owners directly with the U.S. Department of Transportation.

Common Causes of P0304 on FORD MUSTANG

100%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2019
2

What To Do Next

  1. 1
    Check for recalls on YOUR VIN

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.

  2. 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. 3
    Compare repair quotes

    Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.

P0304 on Other Vehicles

Data sourced from the National Highway Traffic Safety Administration (U.S. Department of Transportation) and the SAE J2012 OBD-II standard. Code definitions follow the SAE J2012 / ISO 15031-6 standard. Owner reports are filed directly with NHTSA by vehicle owners. This information is provided for educational purposes only and should not replace professional automotive diagnosis. Always consult a qualified mechanic for vehicle repair decisions.

Last updated: March 2026