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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil cover (if applicable) by unscrewing the bolts.
  2. Disconnect the electrical connector from the ignition coil.
  3. Remove the ignition coil by unscrewing it from the engine.
  4. Extract the spark plug using a spark plug socket and ratchet.
  5. Inspect the spark plug for wear or fouling; replace if necessary.
  6. Install a new spark plug with a gap of 0.043 inches (1.1 mm).
  7. Reinstall the ignition coil and connector.

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. If the spark plug replacement did not resolve the issue, proceed to inspect the ignition coil.
  2. Test the ignition coil with a multimeter to ensure it is functioning correctly (primary and secondary resistance).
  3. Replace the ignition coil with a new one if it is faulty.
  4. Reconnect the ignition coil and cover.

4. Inspect and Clean Fuel Injector

• Sub-steps:
  1. Locate the fuel injector for cylinder 1 and disconnect the electrical connector.
  2. Remove the fuel rail (if necessary) to access the injector.
  3. Clean the injector using a fuel injector cleaning kit or replace it if faulty.
  4. Reinstall the fuel rail and reconnect the injector.

5. Verify Compression

• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert a compression gauge into the spark plug hole.
  3. Crank the engine to measure compression; it should be within manufacturer specifications (usually around 180 psi).
  4. If compression is low, further diagnostics may be needed for internal engine issues.