how to address a P0301 misfire code in my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil cover if applicable.
• Use the spark plug socket to carefully remove the spark plug from cylinder 1.
• Inspect the spark plug for damage or excessive wear.
• Replace the spark plug with a new one that meets OEM specifications (typically NGK or Denso for Toyota).
• Torque the new spark plug to the manufacturer’s specification (usually around 13-15 lb-ft).

3. Check and Replace Ignition Coil

• Tools Required: 10mm socket, ratchet.
• Disconnect the electrical connector from the ignition coil on cylinder 1.
• Remove the securing bolts and lift the ignition coil out.
• Inspect for any cracks or signs of wear.
• Replace it with a new ignition coil if necessary.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect Fuel Injector

• Tools Required: Fuel injector removal tool (if necessary), safety glasses.
• Disconnect the fuel injector connector for cylinder 1.
• Remove the fuel rail if necessary to access the fuel injector.
• Inspect the injector for clogs or leaks.
• Replace the fuel injector if it’s found to be faulty.

5. Compression Test

• Tools Required: Compression gauge.
• Remove the spark plug from cylinder 1.
• Insert the compression gauge into the spark plug hole.
• Crank the engine and record the compression reading.
• Compare the reading to the manufacturer’s specifications (usually around 180 psi).
• If compression is low, further investigation into piston rings or valves is required.