my Toyota Tacoma N300 (2016-Present) has a check engine light with code P0301

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector and unbolt the ignition coil from cylinder 1.
• Remove the spark plug from cylinder 1 using a spark plug socket.
• Inspect the spark plug for wear; replace if necessary (gapped to manufacturer specifications).
• Install a new ignition coil if the old one shows signs of damage or wear.
• Reinstall the ignition components and torque to the specified values.

3. Check and Replace Fuel Injector

• Tools Required: Multimeter or noid light, fuel line removal tool.
• Disconnect the fuel injector connector from cylinder 1.
• Test the injector's resistance with a multimeter; ensure it matches specifications.
• If the injector is faulty, remove it using the fuel line removal tool.
• Install the new fuel injector and reconnect the connector.

4. 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 and record the compression reading.
• Compare the reading to manufacturer specifications; if low, further investigation may be necessary.

5. Reassemble and Test

• Reinstall the engine cover if removed.
• Reconnect the battery.
• Clear the error codes using the OBD-II scanner.
• Start the engine and allow it to reach operating temperature.