P0304 on HONDA CIVIC
What P0304 Means on Your HONDA CIVIC
Real HONDA CIVIC Owner Reports (Source: NHTSA Complaints Database)
"Component or system failure: The vehicle experienced failures involving the engine/ignition system, emissions system, Vehicle Stability Assist (VSA), and power steering. On July 14, 2025, warning messages appeared for “Check Emissions System,” “Check VSA System,” and “Check Power Steering System."
"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."
"Driving on the highway and my check engine light starting to flash. I experienced loss of power and hesitation during acceleration. I got home and scanned my computer and it returned P0304. I then removed the #4 ignition coil and that's when I noticed rust."
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 HONDA CIVIC
Percentages based on NHTSA complaint component analysis for this vehicle.
Complaint Trend by Year
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.
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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.
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3
Compare repair quotes
Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.