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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaner.
• Allow the engine to cool down before starting any work.
• Disconnect the battery negative terminal for safety.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the mounting bolts.
• Detach the electrical connector from the ignition coil.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or damage; replace with a new spark plug if necessary. Use the manufacturer's recommended spark plug gap.
• Reinstall the spark plug and the ignition coil in reverse order, tightening to the manufacturer's torque specification (typically around 13-16 lb-ft).

3. Test and Replace Ignition Coil

• Test the ignition coil for resistance using a multimeter; compare readings with specifications in the service manual.
• If the ignition coil is faulty, replace it with a new unit.
• Reinstall the ignition coil and ensure the electrical connector is securely attached.

4. Perform Compression Test

• Remove the spark plug from cylinder 1 and insert the compression tester.
• Crank the engine for a few seconds and record the compression reading.
• Compare the reading with the specifications in the service manual. If the compression is low, further investigation is necessary, which may include checking for valve issues or head gasket failure.

5. Inspect and Clean Fuel Injector

• If the fuel injector is suspected of being clogged, remove the fuel rail to access the injector.
• Clean the injector using a fuel injector cleaning kit or replace it if necessary.
• Reassemble the fuel rail and ensure all connections are secure.