why does my Toyota Corolla E170 (2013-2019) sound like it has a misfire

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to avoid electrical shock.

2. Replace Spark Plugs

• Sub-steps:
  • Remove the ignition coil cover if applicable.
  • Unscrew and remove the old spark plugs using a spark plug socket.
  • Inspect the spark plug threads and clean if necessary.
  • Install the new spark plugs, ensuring the correct gap as specified in the owner's manual (typically around 0.043 inches).
  • Torque to the manufacturer’s specifications (usually 13-16 ft-lbs).

3. Inspect and Replace Ignition Coils

• Sub-steps:
  • Remove the ignition coils by unscrewing the mounting bolts.
  • Pull the ignition coils out gently from the spark plug wells.
  • Inspect the old coils for damage or carbon tracking.
  • Install new ignition coils, ensuring they are seated properly.
  • Reattach any electrical connectors and secure with the mounting bolts.

4. Clean or Replace Fuel Injectors

• Sub-steps:
  • If using a fuel injector cleaner, follow the product instructions for application.
  • If replacing, disconnect the fuel lines and electrical connectors from the injectors.
  • Remove the old injectors from the fuel rail.
  • Install the new injectors with new O-rings to avoid leaks.
  • Reconnect fuel lines and check for leaks before starting the engine.

5. Test Engine Compression

• Sub-steps:
  • Remove spark plugs to access the cylinders.
  • Insert a compression gauge into the first cylinder and crank the engine.
  • Record the compression reading and repeat for all cylinders.
  • Compare readings to manufacturer specifications (generally between 180-210 psi).
  • If compression is low, investigate further for potential head gasket failure or piston ring issues.