what could be causing my Honda Civic 10th Generation (2016-2021) to misfire at idle?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug gap tool.
• Remove ignition coil covers if applicable.
• Unscrew and remove old spark plugs using a socket wrench.
• Inspect the old spark plugs for signs of wear or damage.
• Install new spark plugs, ensuring they are gapped correctly as per manufacturer specifications (typically around 0.044 inches for Honda Civics).
• Torque the spark plugs to the manufacturer’s specification (usually around 13 lb-ft).

3. Test and Replace Ignition Coils (if necessary)

• Tools Required: Multimeter.
• Remove ignition coils from the engine.
• Test each coil with a multimeter for resistance; refer to the specifications in the service manual (usually around 0.4 to 2.0 ohms for primary resistance).
• Replace any coils that do not meet specifications with new ones.
• Reinstall ignition coils.

4. Check Fuel System

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the ON position (without starting) and check the fuel pressure; it should meet manufacturer specifications (typically around 40-50 psi).
• If pressure is low, inspect the fuel pump and filter; replace as necessary.

5. Inspect and Repair Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Use a smoke machine to locate vacuum leaks or spray carburetor cleaner around vacuum hoses and intake manifold while the engine is running to identify leaks.
• Replace any cracked or damaged hoses and reseal any compromised gaskets.