how to fix P0302 misfire code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, noid light.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil from cylinder 2 by unscrewing the mounting bolt and disconnecting the electrical connector.
  2. Unscrew the spark plug using a socket wrench and inspect it for damage.
  3. Install a new spark plug, ensuring it is gapped to the manufacturer's specifications (typically around 0.043 inches for Toyota).
  4. Torque the new spark plug to 13 lb-ft (18 Nm).

3. Check/Replace Ignition Coil

• Sub-steps:
  1. Test the ignition coil's resistance with a multimeter; check primary and secondary resistance against specifications.
  2. If faulty, remove the ignition coil and replace it with a new unit.
  3. Reconnect the ignition coil and secure it in place.

4. Inspect/Replace Fuel Injector

• Sub-steps:
  1. Remove the fuel injector connector from cylinder 2.
  2. Use a noid light to check for signal to the injector; if no signal, further diagnose the wiring or ECM.
  3. If the injector is faulty, remove it from the fuel rail and replace with a new one.
  4. Reconnect the fuel injector connector.

5. Verify Compression

• Sub-steps:
  1. Remove the spark plug from cylinder 2.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine and record the compression reading; it should be within the manufacturer's specified range (typically 180-200 psi).
  4. If low compression is found, further engine repairs may be necessary.