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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to ensure safety while working on the electrical system.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil cover (if applicable).
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 1.
• Using a spark plug socket, remove the spark plug from cylinder 1.
• Inspect the spark plug for wear (e.g., worn electrodes, fouling).
• If damaged, replace the spark plug with a new one, torque to manufacturer's specifications (typically 13 lb-ft).

3. Test and Replace Ignition Coil

• Reconnect the ignition coil connector to the coil and perform a resistance test using a multimeter (primary side 0.5-1.5 ohms, secondary side 6-15 k ohms).
• If the ignition coil fails the test, replace it with a new coil.
• Reinstall the ignition coil and cover, ensuring all connections are secure.

4. Check and Clean Fuel Injector

• Tools Required: Fuel injector cleaning kit (if applicable).
• Disconnect the fuel injector connector.
• Remove the fuel injector from cylinder 1 (may require removal of the fuel rail).
• Inspect the injector for clogs or leaks.
• If clogged, clean the injector using a fuel injector cleaning kit or replace it with a new one.

5. Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for a few seconds and record the reading.
• Compare with the manufacturer's specifications (typically 150-200 psi). If low, further diagnostics may be needed for internal engine issues.

6. Reassemble and Final Checks

• Reinstall all components in reverse order.
• Reconnect the battery.
• Clear the trouble codes using the OBD-II scanner and perform a test drive.