how to fix P0303 misfire code in Toyota Corolla E140 (2006-2013)

Learn how to diagnose and fix P0303 cylinder 3 misfire in Toyota Corolla. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and securely supported.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench
• Remove the ignition coil from cylinder 3.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for wear, carbon buildup, or damage.
• If necessary, replace the spark plug with a new one (use OEM specifications).
• Torque the spark plug to manufacturer's specifications (typically around 13-16 lb-ft).

3. Inspect and Replace Ignition Coil

• Tools Required: Socket set, torque wrench
• Inspect the ignition coil for any signs of cracks or damage.
• If the ignition coil is faulty, disconnect the electrical connector and remove the coil from the spark plug.
• Install the new ignition coil and reconnect the electrical connector.
• Torque the ignition coil mounting bolts to manufacturer's specifications (usually around 7-10 lb-ft).

4. Test Fuel Injector

• Tools Required: Multimeter, fuel injector tester (optional)
• Disconnect the fuel injector connector for cylinder 3.
• Use a multimeter to check for resistance according to specifications (typically around 12-16 ohms).
• If the injector is faulty, replace it with a new one.
• Reconnect the fuel injector connector after replacement.

5. Reassemble and Test

• Reconnect the negative battery terminal.
• Start the engine and allow it to idle.
• Check for any trouble codes using the OBD-II scanner.