how to fix a misfire in my Toyota Corolla E170 (2013-2019) engine?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the workspace is clean and free of hazards.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket, dielectric grease.
• Remove the ignition coil(s) by unbolting them and disconnecting the electrical connector.
• Use a spark plug socket to remove the spark plugs.
• Inspect the old spark plugs; if they are worn or fouled, replace them with OEM or quality aftermarket plugs.
• Apply dielectric grease to the threads of the new spark plugs and install them. Torque to the manufacturer’s specification (usually around 13 lb-ft).
• Reinstall the ignition coils and reconnect the electrical connectors.

3. Inspect and Replace Ignition Coils (if necessary)

• Tools Required: Socket set.
• Remove the ignition coil(s) as described in Step 2.
• Test each ignition coil for resistance using a multimeter. If any coil is out of specification, replace it.
• Reinstall the new ignition coil(s) by reversing the removal procedure.

4. Clean or Replace Fuel Injectors

• Tools Required: Fuel injector cleaner or replacement injectors, fuel line disconnect tool.
• If injectors are dirty, use a fuel injector cleaner in the fuel system following the product instructions.
• For replacement, relieve fuel system pressure, disconnect fuel lines, and remove the injectors by unbolting them from the fuel rail.
• Install new or cleaned injectors and ensure they are properly seated and secured.

5. Check for Vacuum Leaks

• Tools Required: Smoke tester or carburetor cleaner.
• Inspect all vacuum lines visually for cracks or disconnections.
• Use a smoke tester or spray carburetor cleaner around suspected areas while the engine is running to detect leaks.
• Repair or replace any damaged hoses or gaskets.

6. Perform a Compression Test

• Tools Required: Compression gauge.
• Remove spark plugs and insert the compression gauge into the spark plug hole.
• Crank the engine and note the compression readings; they should be within the manufacturer’s specifications (typically 180-200 psi).
• If compression is low, further internal engine inspection may be necessary.