P0304 Code: 2022 Honda Civic – What It Means & Cost to Fix

2022 Honda Civic P0304 Code: Cylinder 4 Misfire Expert Diagnosis

A P0304 diagnostic code on your 2022 Honda Civic indicates the engine control module has detected repeated misfires in cylinder 4. The 2022 model year introduced the all-new 11th generation Civic.

11th Generation Civic Engines

The 2022 Civic offers the 2.0L naturally aspirated (158 hp) or 1.5L turbocharged (180 hp) four-cylinder. Cylinder 4 is the rearmost cylinder, closest to the firewall on both engines.

Common Causes

  • Ignition Coil Failure: Coil-on-plug units can fail
  • Spark Plug Issues: Turbo model requires specific plugs
  • Boost System Leaks: 1.5L turbo sensitive to leaks
  • Fuel Injector Problems: Direct injection deposits on turbo
  • Carbon Buildup: GDI technology on turbo model

Diagnostic Approach

Use a Honda-compatible scanner for detailed diagnostics. The 2022 Civic has updated engine management. Monitor misfire counts and boost data. Test ignition components systematically.

Repair Solutions

Replace failed ignition coils with Honda OEM or equivalent. Install properly specified spark plugs. Address carbon buildup through professional cleaning. Repair boost leaks on turbo models.

Parts & Tools for This Case

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

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