how to fix the P0301 misfire code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug gapping tool.
• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolts.
• Disconnect the electrical connector from the ignition coil.
• Remove the old spark plug using a spark plug socket.
• Inspect the new spark plug for proper gap (typically 0.043 inches for Toyota).
• Install the new spark plug and torque to 13 lb-ft.
• Reconnect the ignition coil and secure it.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil appears damaged or faulty, replace it.
• Tools Required: Socket set.
• Remove the old ignition coil as described in the previous step.
• Install the new ignition coil and reconnect it.

4. Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaning kit or replacement injector.
• If cleaning: Disconnect fuel lines and remove the fuel injector from cylinder 1.
• Clean the injector using appropriate cleaning solution and tools.
• If replacing: Install the new fuel injector and ensure it is seated properly.

5. Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole and crank the engine.
• Compare the compression reading to the manufacturer's specifications (typically around 180 psi).
• If compression is low, further investigation of the engine internals may be needed.