how to fix P0301 misfire code in my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shock.
• Allow the engine to cool down.

2. Replace Spark Plug

1. Remove the engine cover if applicable.
2. Using a socket wrench, remove the spark plug wire or ignition coil for cylinder 1.
3. Remove the spark plug using a spark plug socket and extension.
4. Inspect the spark plug for damage; if worn or fouled, replace it with a new plug (OEM recommended gap).
5. Install the new spark plug, tightening to 13-16 lb-ft (use a torque wrench).
6. Reattach the ignition coil or spark plug wire.

3. Inspect and Replace Ignition Coil

1. Remove the ignition coil for cylinder 1 by unbolting (if applicable) and disconnecting the electrical connector.
2. Inspect the ignition coil for cracks or carbon tracking.
3. If the coil is faulty, replace it with a new one.
4. Reconnect the electrical connector and securely mount the coil.

4. Test Fuel Injector

1. Locate the fuel injector for cylinder 1 (may require removing the intake manifold).
2. Check the fuel injector connector for corrosion or damage.
3. If necessary, test the injector with a multimeter to ensure it is receiving the proper voltage.
4. If the injector is faulty or clogged, replace it with a new one.

5. Compression Test (If Needed)

1. Remove the spark plug from cylinder 1.
2. Insert a compression gauge into the spark plug hole and crank the engine.
3. Note the compression reading; it should be within the manufacturer's specifications (typically 150-200 psi).
4. If the compression is low, further investigation into internal engine components may be necessary.