how to fix P0301 misfire code in Toyota Corolla E170 (2013-2019)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface with the engine off and cool.
• Disconnect the battery to prevent electrical shocks.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil by unscrewing the bolts and gently pulling it out.
  2. Remove the spark plug using a spark plug socket and ratchet.
  3. Inspect the spark plug for wear, cracks, or fouling.
  4. If damaged, replace it with a new spark plug (specifications: NGK or Denso).
  5. Torque the new spark plug to manufacturer specifications (typically around 13-16 lb-ft).
  6. Reinstall the ignition coil, ensuring it is seated properly.

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. If the spark plug is fine, remove the ignition coil from cylinder 1.
  2. Inspect the ignition coil for any cracks or corrosion.
  3. If faulty, replace it with a new ignition coil (ensure it matches OEM specifications).
  4. Reconnect the ignition coil and secure it with bolts.

4. Check and Clean Fuel Injector

• Sub-steps:
  1. Disconnect the electrical connector from the fuel injector for cylinder 1.
  2. Remove the fuel rail to access the injector (ensure to relieve fuel pressure first).
  3. Inspect the fuel injector for clogs or leaks.
  4. Clean the injector with a fuel injector cleaner or replace it if necessary.
  5. Reinstall the fuel rail and reconnect all components.

5. Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert a compression gauge into the spark plug hole.
  3. Crank the engine several times and record the compression reading.
  4. If the reading is below the manufacturer’s specifications (usually around 150-200 psi), further investigation into mechanical issues is needed.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Spark plug socket
• Compression gauge
• Fuel injector cleaner

Parts Required:

• Spark plug (NGK or Denso)
• Ignition coil (if needed)
• Fuel injector (if required)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical systems.
• Allow the engine to cool before opening any components.