what does the P0301 code mean for my Toyota Camry XV70 (2018-2024)?

Solution

1. Preparation

• Gather necessary tools: OBD-II scanner, spark plug socket, compression tester, multimeter, and basic hand tools.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the mounting bolts and disconnecting the electrical connector.
• Use a spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or fouling. If damaged, replace with a new spark plug, tightening to the manufacturer’s specified torque (usually around 13-15 lb-ft).
• Reinstall the ignition coil, ensuring it is securely connected.

3. Test Ignition Coil

• If the spark plug was not the issue, remove the ignition coil from cylinder 1 and swap it with another cylinder (e.g., cylinder 2).
• Clear the P0301 code and run the engine to see if the check engine light reappears and if the misfire follows the coil.
• If the misfire occurs in the new cylinder, replace the ignition coil with a new one.

4. Perform Compression Test

• If the ignition coil is functioning correctly, perform a compression test on cylinder 1.
• Remove the spark plug and insert the compression tester. Crank the engine for a few seconds and record the reading.
• Compare the compression value with other cylinders; if significantly lower, investigate for possible internal engine issues such as valve problems or piston ring failure.

5. Inspect Fuel Injector

• If the compression test is normal, check the fuel injector for cylinder 1.
• Remove the fuel rail and inspect the injector for clogs or electrical faults using a multimeter.
• If faulty, replace the fuel injector with a new one and ensure proper connections.