How to Replace Ignition Coils on a 2018 Honda Fit (Fix Misfire & Rough Idle)
Step-by-step coil pack replacement with tools, parts list, safety tips, and torque specs (12 Nm / 9 ft-lbs) for 2015, 2016, 2017, 2018, 2019, 2020
How to Replace Ignition Coils on a 2018 Honda Fit (Fix Misfire & Rough Idle)
Step-by-step coil pack replacement with tools, parts list, safety tips, and torque specs (12 Nm / 9 ft-lbs) for 2015, 2016, 2017, 2018, 2019, 2020
🔧 Fit - Ignition Coil Replacement
Your Fit uses one ignition coil per cylinder (4 total). Replacing a bad coil can fix misfires, rough idle, and blinking check-engine lights by restoring a strong spark to the spark plug.
Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours
⚠️ Safety & Precautions
- ⚠️ Let the engine cool fully before starting; coils sit on a hot cylinder head.
- ⚠️ Disconnect the negative battery cable to prevent accidental shorts.
- ⚠️ Pull coils straight up; don’t pry on plastic connectors.
- ⚠️ If the check-engine light is blinking, avoid driving until repaired (can damage the catalytic converter).
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 1/4" drive ratchet
- 6" extension (1/4" drive)
- Torque wrench (in-lb or small ft-lb range)
- Flat trim tool
- Needle-nose pliers
- Shop light
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 4
- Dielectric grease (spark plug boot grease) - Qty: 1
📋 Before You Begin
- Park on level ground, set the parking brake, and open the hood.
- Let the engine cool for at least 30 minutes.
- Use a 10mm socket to disconnect the negative battery cable and move it aside so it can’t spring back.
- Dielectric grease helps prevent moisture and sticking.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the intake duct (if it blocks access)
- Use a flat trim tool to loosen any plastic clips holding the duct/resonator in place.
- Use needle-nose pliers to release any spring clamps, then move the duct out of the way.
- Set all clips/clamps aside where you won’t lose them.
Step 2: Locate the ignition coils
- The coils sit on top of the engine, one per cylinder, with an electrical connector and a small hold-down bolt.
- Use a shop light so you can clearly see each connector tab.
Step 3: Unplug the coil electrical connectors
- Press the connector lock tab with your thumb, then pull the connector straight off.
- If it’s stubborn, use a flat trim tool gently to help start it moving (do not break the tab).
Step 4: Remove the ignition coils
- Use a 10mm socket, 6" extension, and ratchet to remove the coil hold-down bolt.
- Grip the coil and twist slightly, then pull straight up to remove it.
- If a rubber boot stays stuck on the spark plug, pull it out carefully by hand and reinstall it onto the coil you removed.
Step 5: Install the new ignition coils
- Apply a very small amount of dielectric grease inside the rubber boot (a thin film only).
- Push the coil straight down onto the spark plug until it fully seats.
- Install the hold-down bolt by hand first to avoid cross-threading.
- Use a torque wrench and 10mm socket: Torque to 12 Nm (9 ft-lbs).
Step 6: Reconnect everything
- Plug each electrical connector back in until it clicks.
- Reinstall the intake duct/clips you removed using the flat trim tool and needle-nose pliers.
- Reconnect the negative battery cable with the 10mm socket.
✅ After Repair
- Start the engine and let it idle for 1-2 minutes; it should run smooth with no shaking.
- If the check-engine light stays on, you may need to clear stored misfire codes with a scan tool, or the issue may be spark plugs/fuel/air related.
- Take a short test drive and recheck that no connectors are loose.
💰 DIY vs Shop Cost
Shop Cost: $250-$550 (parts + labor)
DIY Cost: $120-$320 (parts only)
You Save: $130-$230 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.0 hours.
🎯 Ready to get started?
HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.


















