how to address P0301 code in my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Tools Required: OBD-II scanner, compression tester, multimeter, socket set, torque wrench.
• Ensure the vehicle is parked on a level surface and the ignition is off. Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the spark plug from cylinder 1 using a socket set.
• Inspect the spark plug for wear, carbon buildup, or damage. Replace if necessary.
• Torque Specification: Install new spark plug to 13 lb-ft.

3. Inspect and Replace Ignition Coil

• Unplug the ignition coil connector for cylinder 1.
• Remove the ignition coil using a socket set.
• Inspect for cracks or carbon tracking. Replace if damaged.
• Reinstall the new ignition coil and reconnect the connector securely.

4. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for about 5 seconds and read the compression value.
• If compression is low (below manufacturer specifications), further investigation is needed for potential valve or piston issues.

5. Check Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a noid light to check if the injector is receiving a signal. If not, check the wiring and ECU.
• If the injector is not functioning, replace it and reconnect the wiring.