why does my Toyota RAV4 have a check engine light and P0301 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery negative terminal to ensure safety.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plug

• Sub-step 1: Remove the engine cover (if applicable) using a socket set.
• Sub-step 2: Unscrew the spark plug using a spark plug socket and ratchet.
• Sub-step 3: Inspect the spark plug for signs of wear (e.g., carbon buildup, damage).
• Sub-step 4: If necessary, replace the spark plug with a new one that meets OEM specifications (usually around 0.044 inches gap).
• Sub-step 5: Reinstall the spark plug and torque it to the manufacturer's specification (typically around 13-15 lb-ft).

3. Inspect and Replace Ignition Coil

• Sub-step 1: Disconnect the electrical connector from the ignition coil for cylinder 1.
• Sub-step 2: Remove the ignition coil using a socket set.
• Sub-step 3: Inspect the coil for cracks or damage; if faulty, replace with a new ignition coil.
• Sub-step 4: Reinstall the ignition coil and reconnect the electrical connector.

4. Test Fuel Injector

• Sub-step 1: Disconnect the fuel injector connector for cylinder 1.
• Sub-step 2: Use a multimeter to test the resistance of the injector; compare to specifications.
• Sub-step 3: If the injector is faulty, remove and replace it.
• Sub-step 4: Reconnect the fuel injector connector.

5. Final Checks

• Sub-step 1: Reconnect the battery negative terminal.
• Sub-step 2: Start the engine and check for smooth operation.
• Sub-step 3: Clear the fault codes with the OBD-II scanner and take the vehicle for a test drive.