The P0304 diagnostic trouble code on your 2024 Toyota Corolla indicates the engine control module has detected consistent misfires in cylinder 4. The 12th generation Corolla offers efficient four-cylinder options.
2024 Corolla Engine Options
The 2024 Corolla offers the 2.0L Dynamic Force four-cylinder (169 hp), 1.8L hybrid system (138 hp), or GR Corolla's 1.6L turbo (300 hp). Cylinder 4 is the rearmost on all inline-4 configurations.
Common Causes
- Ignition Coil Failure: Individual coil-on-plug units can fail
- Spark Plug Issues: Engine-specific requirements
- Fuel Injector Problems: Varies by injection system
- Boost System Leaks: GR Corolla turbo only
- Vacuum Leaks: Intake system integrity
Diagnostic Approach
Use Toyota diagnostic equipment for detailed access. The 2.0L uses D-4S dual injection. Monitor misfire counts. Test ignition components systematically.
Repair Solutions
Replace failed ignition coils with Denso OEM components. Install Toyota-specified spark plugs. GR Corolla requires turbo-specific diagnosis. Dealer service ensures warranty coverage.