how to resolve P0301 misfire code in my Toyota Camry Seventh Generation (2012-2017)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal.
• Allow the engine to cool down completely.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the mounting bolt and gently pulling it out.
• Remove the spark plug using a spark plug socket and ratchet. Inspect for wear, carbon buildup, or damage.
• Replace the spark plug with a new one that meets manufacturer specifications (typically NGK or Denso).
• Reinstall the ignition coil and ensure it is seated properly.

3. Check and Replace Ignition Coil (if necessary)

• If the spark plug is fine, test the ignition coil with a multimeter to check for resistance. Refer to the manufacturer’s specifications for acceptable values.
• If the ignition coil is faulty, replace it with a new OEM part.
• Reinstall the ignition coil and secure it.

4. Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to check the injector's resistance; it should be within the specified range.
• If faulty, replace the fuel injector with a new OEM part.
• Reconnect the fuel injector connector.

5. Compression Test

• If misfire persists, perform a compression test on cylinder 1.
• Remove the spark plug and insert the compression gauge into the spark plug hole.
• Crank the engine and note the reading. Compare it to the manufacturer’s specifications.
• If compression is low, further diagnostics on the engine internals (valve seals, head gasket) may be necessary.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the error codes.
• Start the engine and monitor for any recurring issues.