how to diagnose the P0301 code on my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery to avoid electrical shorts.
• Allow the engine to cool if it has been running.

2. Inspect and Replace Spark Plug

• Remove the ignition coil cover (if applicable) using a socket set.
• Disconnect the connector from the ignition coil.
• Remove the ignition coil from Cylinder 1 using a socket set.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for wear and replace it if necessary with a new OEM spark plug.
• Reinstall the spark plug and torque it to the manufacturer's specifications (typically around 13 ft-lbs).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, inspect the ignition coil for cracks or damage.
• Replace the ignition coil for Cylinder 1 if it shows any signs of failure.
• Reinstall the ignition coil and reconnect the wiring harness.

4. Test Fuel Injector

• Connect a fuel injector tester to Cylinder 1's fuel injector.
• Check for proper operation while cranking the engine.
• Replace the fuel injector if it is not functioning properly.

5. Compression Test (if needed)

• Remove all spark plugs for better access.
• Insert a compression gauge into Cylinder 1.
• Crank the engine and note the compression reading; it should be within the manufacturer's specified range (usually around 150-200 psi).
• If compression is low, further investigation may be necessary (valve issues, head gasket failure).