what does it mean if my Toyota Camry has a check engine light with P0301

Solution

1. Preparation

• Tools Required: OBD-II scanner, spark plug socket, ratchet, compression tester, multimeter, fuel injector cleaner.
• Disconnect the negative battery terminal to ensure safety.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Use a spark plug socket to carefully remove the spark plug from cylinder 1.
• Inspect the old spark plug for signs of wear (e.g., fouling, damage).
• Install a new spark plug, ensuring it is gapped correctly (typically 0.043 inches for most Toyota engines).
• Torque the spark plug to the manufacturer’s specifications (usually around 13 lb-ft).

3. Check and Replace Ignition Coil

• Disconnect the ignition coil connector.
• Remove the ignition coil from cylinder 1.
• Test the ignition coil with a multimeter for resistance (consult service manual for specific values).
• Replace the ignition coil if it is out of specification.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Remove the fuel rail if necessary to access the fuel injector for cylinder 1.
• Inspect the fuel injector for clogs or leaks.
• Use fuel injector cleaner to clean the injector or replace if defective.
• Reinstall the fuel rail and ensure all connections are secure.

5. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine and read the pressure on the gauge (specifications vary by engine; typically around 180 psi).
• If compression is low, further diagnostics on the engine may be necessary.