how to resolve the check engine light on my Toyota Camry XV70 (2018-2024) for code P0301?

Solution

1. Preparation

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

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket, dielectric grease.
• Remove the ignition coil for cylinder 1 by unbolting it and disconnecting the electrical connector.
• Unscrew the old spark plug using a spark plug socket.
• Inspect the old spark plug for signs of wear (e.g., carbon build-up or damage).
• Install the new spark plug, applying a small amount of dielectric grease on the threads.
• Torque the spark plug to the manufacturer-specified value (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test Ignition Coil

• Tools Required: Digital multimeter.
• Disconnect the ignition coil for cylinder 1 again.
• Measure the resistance across the primary and secondary terminals.
• Compare the readings to the specifications in the service manual. Replace if out of spec.

4. Inspect and Test Fuel Injector

• Tools Required: Fuel injector tester or multimeter.
• Disconnect the fuel injector connector for cylinder 1.
• Perform a resistance test; compare to specifications.
• If faulty, replace the fuel injector, ensuring to clean any debris in the injector port.

5. Check for Vacuum Leaks

• Visually inspect the intake manifold and all vacuum lines connected to cylinder 1.
• Use a smoke machine or carburetor cleaner to identify leaks while the engine is running.
• Repair or replace any damaged or leaking components.

6. Conduct Compression Test

• Tools Required: Compression gauge.
• Remove the spark plug from cylinder 1.
• Insert the compression gauge into the spark plug hole.
• Crank the engine and record the highest compression reading.
• Compare the reading to the manufacturer’s specifications.