what could cause a misfire in my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, fuel pressure gauge, torque wrench.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Spark Plugs

• Remove the ignition coils using a socket set.
• Remove the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear and replace if necessary.
  • Torque specifications: Install new spark plugs to 13 lb-ft (17.6 Nm).
• Reinstall the ignition coils securely.

3. Test and Replace Ignition Coils (if necessary)

• Use a multimeter to test the resistance of each ignition coil.
  • Compare readings to manufacturer specifications.
• If any coil is out of spec, replace it with a new one.
• Ensure proper seating and electrical connection of new coils.

4. Clean or Replace Fuel Injectors

• Remove the fuel rail to access the fuel injectors.
• Inspect each injector for clogs; use a fuel injector cleaner if necessary.
• If cleaning does not resolve issues, replace faulty injectors with new ones.
• Reinstall the fuel rail and ensure all connections are secure.

5. Check Fuel Pressure

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start) and check the pressure reading.
  • Ensure it matches manufacturer specifications.
• If low, inspect or replace the fuel pump as necessary.