What is the P0302 Code? Diagnosing and Fixing Cylinder 2 Misfires

What is the P0302 Code? Diagnosing and Fixing Cylinder 2 Misfires

The P0302 code stands for “Cylinder 2 Misfire Detected.” This means that the vehicle’s powertrain control module (PCM) has detected that cylinder 2 is not contributing to the engine’s power output as it should. A misfire occurs when the air-fuel mixture in the cylinder fails to ignite properly, leading to a loss of power and potentially increased emissions.

Top 20 Vehicles Commonly Affected by P0302

While this code can appear in many vehicles, here are 20 models that frequently experience P0302 issues:

  1. Honda Civic
  2. Toyota Camry
  3. Ford F-150
  4. Chevrolet Silverado
  5. Honda Accord
  6. Toyota Corolla
  7. Nissan Altima
  8. Ford Focus
  9. Hyundai Elantra
  10. Volkswagen Jetta
  11. BMW 3 Series
  12. Mazda3
  13. Subaru Impreza
  14. Jeep Grand Cherokee
  15. Dodge Ram
  16. Chrysler 300
  17. Audi A4
  18. Mercedes-Benz C-Class
  19. Kia Optima
  20. Lexus RX

Implications for Vehicle Performance and Emissions

A P0302 code can have significant impacts on your vehicle’s performance and emissions:

  • Reduced Power: With one cylinder not firing correctly, your engine loses a substantial amount of power.
  • Decreased Fuel Efficiency: Misfires can cause your vehicle to consume more fuel than necessary.
  • Increased Emissions: Unburned fuel from the misfiring cylinder can enter the exhaust system, potentially damaging the catalytic converter and increasing harmful emissions.
  • Engine Damage: If left unaddressed, continuous misfires can lead to more severe engine problems over time.

Diagnosing and Fixing P0302

Diagnosing a P0302 code typically involves the following steps:

  1. Verify the code: Use an OBD-II scanner to confirm the P0302 code and check for any additional codes.
  2. Visual inspection: Check for obvious issues like loose wires or damaged components.
  3. Check ignition system: Inspect spark plugs, ignition coils, and spark plug wires for cylinder 2.
  4. Fuel system check: Ensure the fuel injector for cylinder 2 is functioning correctly.
  5. Compression test: Perform a compression test on cylinder 2 to check for mechanical issues.
  6. Advanced diagnostics: If the above steps don’t resolve the issue, more advanced diagnostic techniques may be necessary.

Key Symptoms and Solutions


  • Check engine light on or flashing
  • Engine running rough or vibrating
  • Decreased power and acceleration
  • Poor fuel economy
  • Unusual exhaust odor


  • Replace faulty spark plugs
  • Replace damaged ignition coils
  • Clean or replace fuel injectors
  • Repair vacuum leaks
  • Address mechanical engine issues (if present)

Frequently Asked Questions

Q: Is it safe to drive with a P0302 code? A: While you can drive short distances, it’s not recommended to continue driving with a misfire. It can lead to catalytic converter damage and decreased fuel efficiency.

Q: What are the potential repair costs for a P0302 code? A: Costs can vary widely depending on the cause. Simple spark plug replacements might cost $100-$200, while more complex issues could run $500 or more.

Q: How can I prevent P0302 from occurring in the future? A: Regular maintenance is key. Follow your vehicle’s recommended service schedule, particularly for spark plug and ignition system components.


The P0302 code, while common, should not be ignored. Addressing this issue promptly can prevent more severe engine damage, maintain your vehicle’s performance, and ensure compliance with emission standards. If you’re not comfortable diagnosing or repairing the issue yourself, don’t hesitate to consult a professional mechanic. Remember, maintaining your vehicle’s health not only saves you money in the long run but also contributes to a cleaner environment.

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