how to fix the P0301 code on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, gap gauge.
• Remove the ignition coil and spark plug from cylinder 1.
• Inspect the spark plug for wear, carbon buildup, or damage.
• If necessary, replace the spark plug with a new one, ensuring it is gapped correctly to manufacturer specifications (usually around 0.043 inches for Toyota).
• Reinstall the ignition coil.

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil for resistance using a multimeter.
• If the coil is faulty, replace it with a new ignition coil specifically designed for the Toyota Corolla E170.
• Reinstall the ignition coil securely.

4. Perform Compression Test

• Tools Required: Compression gauge.
• Remove the spark plug from cylinder 1 and insert the compression gauge.
• Crank the engine for a few seconds and record the compression reading.
• Compare the reading to the manufacturer’s specifications (typically around 170 psi for a Toyota engine).
• If the compression is low, diagnose potential causes (e.g., worn piston rings, valve issues).

5. Inspect Fuel Injectors

• If the ignition components are functioning properly, inspect the fuel injector for cylinder 1.
• Clean or replace the fuel injector if clogged or malfunctioning.
• Reassemble any removed components.