how to fix the P0302 misfire code on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Needed: Socket set, torque wrench, spark plug gap tool.
• Remove the ignition coil for cylinder 2:
  1. Unplug the electrical connector from the ignition coil.
  2. Remove the retaining bolts and lift the coil out.
• Remove the spark plug:
  1. Use a spark plug socket to unscrew and remove the spark plug.
  2. Inspect the spark plug for signs of wear or fouling.
• Install a new spark plug:
  1. Set the gap on the new spark plug to the manufacturer’s specification (typically around 0.044 inches).
  2. Carefully thread the new spark plug into the cylinder head by hand, then tighten to the manufacturer’s torque specification (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil (if necessary)

• Tools Needed: Socket set, torque wrench.
• If the spark plug is fine, test or replace the ignition coil:
  1. Use a multimeter to test the coil’s resistance according to specifications.
  2. If faulty, install a new ignition coil by reversing the removal steps.

4. Clean or Replace Fuel Injector (if necessary)

• Tools Needed: Fuel injector cleaner, socket set.
• Remove the fuel rail to access the injector:
  1. Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.
  2. Disconnect fuel lines and electrical connectors from the fuel rail.
  3. Remove the fuel rail bolts and lift it off.
• Inspect or clean the fuel injector for cylinder 2. Replace if clogged or malfunctioning.

5. Conduct Compression Test (if necessary)

• Tools Needed: Compression tester.
• Perform a compression test on cylinder 2:
  1. Remove the spark plug and crank the engine to obtain compression readings.
  2. Compare the results to the manufacturer’s specifications (generally around 180-200 psi).
  3. If compression is low, further investigation into potential mechanical issues may be needed.