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

Solution

1. Preparation

• Gather required tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the negative battery terminal.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench, gap gauge.
• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolt and gently pulling it out.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for wear; if damaged, replace it with a new one, ensuring it is gapped correctly (typically 0.043 inches).
• Reinstall the spark plug and torque it to the manufacturer's specification (usually around 13-16 lb-ft).

3. Test and Replace Ignition Coil

• Tools Required: Multimeter.
• Reconnect the ignition coil connector and measure the resistance across the coil terminals with a multimeter.
• If the resistance is outside the manufacturer's specified range (usually between 0.4 - 0.6 ohms), replace the ignition coil.
• Install the new ignition coil and secure it with the retaining bolt.

4. Inspect and Replace Fuel Injector

• Tools Required: Fuel injector puller (if necessary), fuel line tool.
• Disconnect the fuel injector connector and the fuel line.
• Remove the fuel injector from cylinder 1 by pulling it out of the intake manifold.
• Inspect for clogs and replace with a new injector if necessary.
• Reinstall the injector, reconnect the fuel line, and ensure all connections are secure.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach normal operating temperature.