how to fix P0301 misfire code in my Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather tools and parts for the repair.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the negative battery terminal to ensure safety.

2. Inspect and Replace Spark Plug

1. Remove the engine cover if applicable using a socket set.
2. Disconnect the ignition coil connector from cylinder 1.
3. Unbolt and remove the ignition coil from cylinder 1.
4. Use a spark plug socket to remove the spark plug from cylinder 1.
5. Inspect the old spark plug for signs of wear or damage; replace if necessary.
6. Install a new spark plug (specifications: gap 0.043 inches) and torque it to 13 lb-ft.
7. Reinstall the ignition coil and reconnect the ignition coil connector.

3. Check and Replace Fuel Injector (if necessary)

1. If the spark plug and ignition coil are functioning well, proceed to the fuel injector.
2. Disconnect the fuel injector connector from cylinder 1.
3. Remove the fuel rail by unbolting it and carefully lifting it out, ensuring no fuel spills.
4. Remove the old fuel injector from cylinder 1 and inspect for clogs.
5. Install a new fuel injector and ensure it seats properly.
6. Reassemble the fuel rail and reconnect the fuel injector connector.

4. Verify Compression (if misfire persists)

1. Remove the spark plug again from cylinder 1.
2. Insert a compression gauge into the spark plug hole.
3. Crank the engine for a few seconds and record the reading; it should be within the manufacturer’s specification (around 180 psi).
4. If low, consider further investigation of the engine internals (valves, piston rings).