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

2023 Honda HR-V P0304: Cylinder 4 Misfire Troubleshooting Guide

When your 2023 Honda HR-V displays the P0304 code, the powertrain control module has identified consistent misfires in cylinder 4. The completely redesigned 2nd generation HR-V features a new 2.0L engine.

2023 HR-V Powertrain

The redesigned 2023 HR-V uses a 2.0L naturally aspirated i-VTEC four-cylinder producing 158 horsepower. Cylinder 4 is the rearmost on this inline-4. This port-injection engine avoids carbon buildup concerns.

Typical Causes

  • Ignition Coil Problems: Coil-on-plug failures
  • Spark Plug Condition: Honda-specific requirements
  • Fuel Injector Issues: Port injection system
  • Vacuum Leaks: Intake system integrity
  • Valve Adjustment: i-VTEC valve clearance

Diagnostic Process

Use Honda diagnostic equipment for the new platform. Monitor misfire counts. Port injection simplifies fuel system diagnosis. Test ignition components systematically.

Repair Recommendations

Replace faulty ignition coils with OEM parts. Install properly specified spark plugs. Repair vacuum leaks. Dealer service ensures warranty coverage.

Parts & Tools for This Case

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

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