how to fix the P0302 misfire on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, noid light.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before beginning work.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 2 by unscrewing the retaining bolts.
• Disconnect the electrical connector from the ignition coil.
• Remove the old spark plug using a spark plug socket.
• Inspect the spark plug hole for debris and clean as necessary.
• Install the new spark plug, ensuring it is gapped correctly (typically 0.043 inches for Corolla).
• Torque the spark plug to manufacturer specifications (usually around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test Ignition Coil

• If the spark plug replacement does not resolve the issue, test the ignition coil.
• Use a multimeter to check the primary and secondary resistance of the coil against manufacturer specifications.
• If the ignition coil is faulty, replace it with a new one.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect and Replace Fuel Injector (if necessary)

• If the ignition components are functioning correctly, check the fuel injector for cylinder 2.
• Remove the fuel rail according to the manufacturer’s instructions.
• Use a noid light to check for proper signal to the injector.
• If the injector is not functioning, replace it with a new one.
• Reassemble the fuel rail and reconnect all components.

5. Perform Compression Test

• If all previous steps fail to resolve the issue, perform a compression test on cylinder 2.
• If compression is low, further investigation into the internal engine components may be necessary.
• Address any internal engine issues such as valve problems or piston ring wear.