how to fix P0301 code for my Toyota RAV4 XA40 (2013-2018)?

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaner.
• Disconnect the battery to safeguard against electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Replace Spark Plug

• Remove the ignition coil for cylinder 1 using a socket set.
• Unscrew and remove the spark plug.
• Inspect the spark plug for wear or fouling; replace if necessary.
• Install a new spark plug, ensuring it is gapped according to manufacturer specifications (typically 0.043 inches for a RAV4).
• Torque the spark plug to the specified value (usually around 13 lb-ft).

3. Check and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil using a multimeter.
• If the coil is faulty, remove it and replace it with a new ignition coil.
• Reinstall the ignition coil, ensuring it is seated correctly and connected securely.

4. Inspect and Clean Fuel Injector

• Check the fuel injector for cylinder 1 by disconnecting the electrical connector and fuel line.
• Use a fuel injector cleaner to clean the injector or replace it if necessary.
• Reconnect the fuel line and electrical connector, ensuring they are secure.

5. Compression Test

• To perform a compression test, remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole and crank the engine.
• Record the compression reading; it should be within the manufacturer's specifications (usually around 170-210 psi).
• If compression is low, further investigation into piston rings or valve seals may be required.

6. Final Checks

• Reconnect the battery.
• Clear the P0301 code with the OBD-II scanner.
• Start the engine and observe for any immediate issues.