P0304 on HYUNDAI ELANTRA — Cylinder 4 Misfire Detected

Q: "What does P0304 mean on a HYUNDAI ELANTRA?"

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

Q: "What are the most common causes of P0304 on HYUNDAI ELANTRA?"

"Based on 4 NHTSA reports, the most commonly cited components are: Engine, Power Train,Engine. These percentages are based on the component field in owner complaints."

Q: "Is P0304 serious on my HYUNDAI ELANTRA?"

"Of 4 NHTSA reports for this code on HYUNDAI ELANTRA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my HYUNDAI ELANTRA 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 HYUNDAI ELANTRA

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.

4 HYUNDAI ELANTRA owners have reported this issue to NHTSA across model years 2011-2019. Most reports come from the 2011, 2017 model years. The most commonly reported component is Engine (75.0% of reports).

Real HYUNDAI ELANTRA Owner Reports

Source: NHTSA Complaints Database

"Drove vehicle to dealer, boucher hyundia of waukesha after the check engine light would go on and off with codes p2096 and p0304. codes are related to cylinder 3 and 4 misfires. dealer found engine making a noise from lower end and recommends an engine replacement."

— 2011 HYUNDAI ELANTRA owner · ENGINE · Filed 07/22/2019

"Check engine light on with diagnostic error code P0304 cylinder 4 misfire detected ignition coil"

— 2017 HYUNDAI ELANTRA owner · POWER TRAIN,ENGINE · Filed 01/28/2022

"I am filing this Vehicle Owner's Questionnaire (VOQ) regarding critical safety defects in my 2018 Hyundai Elantra related to: - Recurrent ignition coil pack failures (3 replacements since 10/2018) - Engine stalling at low speeds (6 incidents since 10/2018) - Dealer refusal to apply TSB 20-01-008H EC"

— 2018 HYUNDAI ELANTRA owner · ENGINE · Filed 06/08/2025

"I purchased my 2019 Hyundai Elantra from a third-party dealer (Mike Carlson Motor Company in Haltom City, TX) on [XXX]. I have kept the oil changed on a regular basis since I purchased it."

— 2019 HYUNDAI ELANTRA owner · ENGINE · Filed 07/16/2025

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

📊 Complaint Trend by Model Year

1

'11

1

'17

1

'18

1

'19

Common Causes on HYUNDAI ELANTRA

Based on NHTSA complaint component analysis for this vehicle.

ENGINE 75%

POWER TRAIN,ENGINE 25%

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 HYUNDAI ELANTRA? ▾

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

What are the most common causes of P0304 on HYUNDAI ELANTRA? ▾

Based on 4 NHTSA reports, the most commonly cited components are: Engine, Power Train,Engine. These percentages are based on the component field in owner complaints.

Is P0304 serious on my HYUNDAI ELANTRA? ▾

Of 4 NHTSA reports for this code on HYUNDAI ELANTRA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my HYUNDAI ELANTRA 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.