P0304 Code: 2018 Toyota Camry – What It Means & Cost to Fix

2018 Toyota Camry P0304 Code: Cylinder 4 Misfire Expert Diagnosis

When your 2018 Toyota Camry displays the P0304 code, the engine control module has identified consistent misfires in cylinder 4. The first year of the 8th generation Camry introduced new TNGA-based engines.

2018 Camry Engine Options

The 2018 Camry offers the 2.5L Dynamic Force four-cylinder (203 hp), 2.5L hybrid (208 hp), or 3.5L V6 (301 hp). All feature Toyota's efficient direct injection systems. Cylinder 4 location varies by engine.

Common Causes

  • Ignition Coil Failure: Age-related degradation common
  • Spark Plug Wear: May be approaching service interval
  • Fuel Injector Issues: Direct injection deposits
  • Carbon Buildup: Possible on 2.5L non-D-4S models
  • Vacuum Leaks: Gasket and hose deterioration

Diagnostic Approach

Use a Toyota-compatible scanner for detailed diagnostics. At this age, systematic testing is important. Monitor misfire counts. Test ignition components.

Repair Solutions

Replace aging ignition coils with quality parts. Install new spark plugs if at service interval. Address carbon buildup if present. Repair vacuum leaks.

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