how to diagnose my Toyota Corolla E210 (2019-2024) with a P0302 code

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaning kit.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Components

a. Ignition Coil

• Remove the engine cover (if applicable) to access the ignition coil.
• Disconnect the electrical connector from the ignition coil on cylinder 2.
• Remove the bolt securing the ignition coil and pull it out gently.
• Install the new ignition coil and torque it to manufacturer's specifications (typically around 8-10 ft-lbs).
• Reconnect the electrical connector.

b. Spark Plug

• Use a spark plug socket to remove the spark plug from cylinder 2.
• Inspect the spark plug for wear; replace if necessary (gapped to manufacturer's specifications).
• Install the new spark plug and torque to 12-15 ft-lbs.

c. Fuel Injector

• Carefully disconnect the fuel injector connector for cylinder 2.
• Remove the fuel rail (if necessary) to access the injector.
• Replace the fuel injector and ensure it is seated properly.
• Reconnect the fuel line and injector connector.

3. Compression Test

• Remove the spark plug from cylinder 2.
• Insert the compression tester into the spark plug hole and crank the engine.
• Record the compression reading; it should be within the manufacturer's specifications (usually around 170-200 psi).
• If compression is low, further investigation is necessary for potential mechanical issues.