how to diagnose a P0301 code in my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts during repair.

2. Replace Spark Plug

• Remove the spark plug cover if necessary.
• Use a spark plug socket and ratchet to remove the spark plug from cylinder 1.
• Inspect the old spark plug for wear and compare it to manufacturer's specifications.
• Install a new spark plug (ensure the gap is set to manufacturer specifications).
• Torque the spark plug to the manufacturer's specified value (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• Remove the ignition coil connector and unscrew the mounting bolts.
• Carefully pull out the ignition coil from the cylinder head.
• Inspect the ignition coil for cracks or carbon tracking.
• If necessary, replace it with a new ignition coil.
• Reinstall the ignition coil, ensuring it is seated properly and reconnect the connector.

4. Test Fuel Injector

• Use a fuel injector tester to check the operation of the fuel injector for cylinder 1.
• If the injector is not functioning, replace it with a new injector.
• Reinstall the fuel injector, ensuring proper seating and connection.

5. Compression Test (if necessary)

• If misfire persists, perform a compression test.
• Remove the spark plug and insert the compression gauge into cylinder 1.
• Crank the engine and note the reading; compare it to manufacturer specifications.
• If compression is low, further investigation into internal engine components may be required.