P0303 on HONDA CIVIC — Cylinder 3 Misfire Detected

Q: "What does P0303 mean on a HONDA CIVIC?"

"P0303 indicates: Cylinder 3 Misfire Detected. This is a ignition system code. 2 HONDA CIVIC owners have reported this to NHTSA."

Q: "What are the most common causes of P0303 on HONDA CIVIC?"

"Based on 2 NHTSA reports, the most commonly cited components are: Engine. These percentages are based on the component field in owner complaints."

Q: "Is P0303 serious on my HONDA CIVIC?"

"Of 2 NHTSA reports for this code on HONDA CIVIC, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my HONDA CIVIC shows P0303?"

"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 P0303 Means on Your HONDA CIVIC

P0303 is a diagnostic trouble code indicating: Cylinder 3 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.

2 HONDA CIVIC owners have reported this issue to NHTSA across model years 2016-2018. Most reports come from the 2016, 2018 model years. The most commonly reported component is Engine (100.0% of reports).

Real HONDA CIVIC Owner Reports

Source: NHTSA Complaints Database

"Driving on highway to work when check engine light came on in addition to "Emissions System Problem", "Hill Start Assist", "Power Steering Issue", etc. When scanned for codes it showed misfire codes P0300, P0301, P0302, P0303, P0304."

— 2016 HONDA CIVIC owner · ENGINE · Filed 11/11/2024

"The contact owns a 2018 Honda Civic. The contact stated while driving approximately 20 MPH, several unknown warning lights illuminated and the vehicle started to idle very rough. The contact had taken the vehicle to a local dealer however, the vehicle was not diagnosed."

— 2018 HONDA CIVIC owner · ENGINE · Filed 02/22/2021

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

📊 Complaint Trend by Model Year

1

'16

1

'18

Common Causes on HONDA CIVIC

Based on NHTSA complaint component analysis for this vehicle.

ENGINE 100%

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 P0303 mean on a HONDA CIVIC? ▾

P0303 indicates: Cylinder 3 Misfire Detected. This is a ignition system code. 2 HONDA CIVIC owners have reported this to NHTSA.

What are the most common causes of P0303 on HONDA CIVIC? ▾

Based on 2 NHTSA reports, the most commonly cited components are: Engine. These percentages are based on the component field in owner complaints.

Is P0303 serious on my HONDA CIVIC? ▾

Of 2 NHTSA reports for this code on HONDA CIVIC, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my HONDA CIVIC shows P0303? ▾

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.