how to fix the P0301 misfire code in my Toyota Corolla E170 (2013-2019)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench
• Remove the ignition coil from cylinder 1 by unbolting it and disconnecting the electrical connector.
• Use a spark plug socket to remove the old spark plug from cylinder 1.
• Inspect the spark plug for wear. If worn or fouled, replace with a new spark plug, ensuring proper gap (typically 0.043 inches).
• Torque the new spark plug to the manufacturer's specifications (around 13 lb-ft).

3. Replace Ignition Coil

• Tools Required: Socket set, torque wrench
• If the ignition coil is suspected to be faulty, remove the ignition coil from cylinder 1.
• Install a new ignition coil and ensure it is properly seated.
• Torque the mounting bolts to the manufacturer’s specifications (typically around 80 in-lbs).

4. Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaner or new injector, fuel line disconnect tool
• If the fuel injector is clogged, use a fuel injector cleaner to clean the injector according to the product instructions.
• If cleaning does not resolve the issue, remove the fuel injector using a fuel line disconnect tool and install a new injector.
• Ensure proper seating and reconnect the fuel lines.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner
• Inspect all vacuum lines connected to the intake manifold. Use a smoke machine to detect leaks or spray carburetor cleaner around suspected areas; if the idle changes, a leak is present.
• Replace any damaged vacuum lines as necessary.