how to fix P0301 misfire code in my Toyota Camry XV50 (2012-2017)?

Solution

1. Preparation

• Gather necessary tools and parts, ensuring you have access to the vehicle's service manual.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down.

2. Inspect Spark Plug

• Tools Required: Socket set, torque wrench
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 1.
• Unscrew the spark plug using a spark plug socket and inspect it for wear or deposits.
• Replace the spark plug if it shows signs of damage or excessive wear (recommended gap: 0.043 inches).

3. Check Ignition Coil

• Swap the ignition coil from cylinder 1 with the ignition coil from a known good cylinder.
• Reconnect the ignition coil connector and clear the trouble codes.
• Start the engine and check if the misfire code moves to the cylinder where the coil was swapped.

4. Test Fuel Injector

• Tools Required: Noid light or multimeter
• Disconnect the fuel injector connector from cylinder 1.
• Connect a noid light to the injector connector or use a multimeter to check for voltage.
• If no signal is present, trace wiring back to the ECM for faults.

5. Measure Compression

• Tools Required: Compression tester
• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for several seconds and record the pressure. Compare with specifications (typically between 180-200 psi).
• If compression is low, further investigation into piston rings or valves may be necessary.