how to fix a check engine light related to P0301 in my Toyota Camry?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, fuel injector cleaner.
• Ensure the vehicle is parked on a level surface and the engine is cool before starting repairs.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Unbolt and carefully lift out the ignition coil.
• Remove the spark plug using a spark plug socket:
  • Inspect for wear or damage (carbon buildup, cracks).
• Replace with a new spark plug if necessary:
  • Set the gap according to manufacturer specifications, typically around 0.043 inches.
  • Torque to manufacturer specification (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil shows signs of damage, replace it:
  • Install the new ignition coil by reversing the removal process.
  • Ensure the electrical connector is securely attached.

4. Check and Clean Fuel Injector

• Use a fuel injector cleaner to clean the injector for cylinder 1:
  • Follow the product instructions for application.
• If cleaning does not resolve the issue, consider replacing the injector:
  • Remove the fuel rail if necessary, then replace the faulty injector with a new one.
  • Reinstall the fuel rail and ensure all connections are secure.

5. Perform a Compression Test

• If misfire persists, perform a compression test on cylinder 1:
  • Remove the spark plug and install the compression tester.
  • Crank the engine and note the reading.
  • If compression is below manufacturer specifications, consult further for potential internal engine issues.