my Toyota Corolla E140 (2006-2013) has a check engine light with code P0302, what does it mean?

Solution

1. Preparation

• Gather necessary tools and materials.
• Disconnect the negative terminal of the battery to ensure safety.
• Gather replacement parts if needed (spark plugs, ignition coils, fuel injector).

2. Inspect and Replace Ignition Components

• Spark Plug Replacement:

  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for cylinder 2.
  3. Remove the ignition coil using a socket set.
  4. Unscrew and remove the spark plug from cylinder 2.
  5. Inspect the old spark plug for wear; replace it with a new spark plug, ensuring the gap is set to manufacturer specifications (typically 0.043 inches).
  6. Reinstall the ignition coil and reconnect the connector.

• Ignition Coil Replacement (if necessary):

  1. If the ignition coil appears damaged, replace it with a new unit.
  2. Follow the same removal and installation steps as above.

3. Inspect and Replace Fuel Injector

1. Disconnect the fuel injector connector for cylinder 2.
2. Remove the fuel rail if necessary, ensuring to relieve fuel pressure first.
3. Remove the fuel injector and inspect for clogs or damage.
4. Replace with a new fuel injector if necessary, lubricating the O-rings with clean engine oil before installation.
5. Reassemble the fuel rail and reconnect the fuel injector connector.

4. Perform Compression Test

1. Remove the spark plug from cylinder 2.
2. Insert a compression gauge into the spark plug hole.
3. Crank the engine and note the compression reading; compare it to manufacturer's specifications (typically 180-200 psi).
4. If the compression is low, further investigation into internal engine components may be required.

5. Reassemble and Clear Codes

1. Reinstall any components removed during the diagnostic and repair process.
2. Reconnect the negative battery terminal.
3. Use an OBD-II scanner to clear the trouble codes.