how do I fix a misfire in my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety during repairs.

2. Replace Spark Plugs

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connectors from the spark plug wells.
  3. Use the spark plug socket to carefully remove the old spark plugs.
  4. Inspect the threads in the cylinder head for damage; clean if necessary.
  5. Install new spark plugs, ensuring they are gapped correctly (refer to specifications).
  6. Torque the spark plugs to the manufacturer's specification (typically around 13-16 lb-ft).

3. Inspect and Replace Ignition Coils

• Tools Required: Ratchet, extension, possibly a torque wrench.
• Sub-steps:
  1. Remove the bolts securing the ignition coils.
  2. Carefully pull the ignition coils from the spark plug wells.
  3. Inspect connectors and replace if any signs of wear or damage are found.
  4. Install new ignition coils, ensuring they click into place.
  5. Reattach any bolts and torque to specifications if needed.

4. Clean or Replace Fuel Injectors

• Tools Required: Fuel injector cleaner kit (if cleaning), ratchet.
• Sub-steps:
  1. If cleaning, connect the fuel injector cleaner kit to the fuel rail following the manufacturer's instructions.
  2. If replacing, disconnect the fuel lines (use caution as fuel may spill).
  3. Remove the retaining clips and electrical connectors of the fuel injectors.
  4. Replace with new injectors, ensuring they are seated correctly.
  5. Reconnect fuel lines and check for leaks.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and allow it to idle; check for misfires.
• If applicable, clear any error codes using the OBD-II scanner and take the vehicle for a test drive.