P0304 Code: 2023 Honda – What It Means & Cost to Fix

2023 Honda Ridgeline P0304: Cylinder 4 Misfire Troubleshooting

The P0304 diagnostic trouble code on your 2023 Honda Ridgeline indicates the powertrain control module has detected consistent misfires in cylinder 4. The refreshed Ridgeline continues with the proven 3.5L V6.

2023 Ridgeline Powertrain

The 2023 Ridgeline uses the J35Y6 3.5L V6 producing 280 horsepower. The refreshed model features updated styling while maintaining the reliable V6 architecture. Cylinder 4 is on the rear bank.

Typical Causes

  • Ignition Coil Problems: Coil-on-plug failures
  • Spark Plug Condition: Honda-specific requirements
  • VCM Operation: Cylinder deactivation
  • Fuel Injector Issues: Direct injection deposits
  • Carbon Accumulation: GDI valve deposits

Diagnostic Process

Use Honda diagnostic equipment for detailed access. Monitor VCM operation and misfire data. Test ignition components systematically.

Repair Recommendations

Replace faulty ignition coils with OEM parts. Install properly specified spark plugs. Dealer service for warranty coverage.

Parts & Tools for This Case

Based on our investigation, these parts may be needed for this repair.

As an affiliate, we may earn from qualifying purchases. This does not affect our recommendations. Learn more

Got Another Mystery?

"The game is afoot!" Let our AI detective investigate your next automotive case.

Open a New Case