how to fix P0301 code in Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if necessary.
• Disconnect the ignition coil connector and remove the ignition coil.
• Use a spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug for signs of wear or fouling.
• Replace with a new spark plug, ensuring it is gapped according to manufacturer specifications (usually around 0.044 inches).
• Torque the spark plug to the specified value (typically around 13 lb-ft).
• Reinstall the ignition coil and connector.

3. Check and Replace Ignition Coil (if necessary)

• Tools Required: Socket set.
• Remove the ignition coil from cylinder 1 (if it was not already removed).
• Use a multimeter to test the resistance of the ignition coil; compare results with manufacturer specifications.
• If the ignition coil is faulty, replace it with a new one.
• Reinstall the ignition coil and secure the connector.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaning kit or replacement injector.
• Disconnect the fuel injector connector and remove the fuel injector from cylinder 1.
• Inspect the injector for clogs or leaks.
• If cleaning, use a fuel injector cleaning solution; if damaged, replace with a new injector.
• Reinstall the injector and secure the connector.

5. Perform Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 1 and install the compression tester.
• Crank the engine and record the compression reading.
• Compare the reading with manufacturer specifications (usually around 180-200 psi).
• If compression is low, further diagnostics for potential internal engine issues are needed.