How to Replace Ignition Coils on a 2018 Honda Odyssey (Fix Misfire & Rough Idle)
Step-by-step ignition coil replacement with required tools, parts list, safety tips, and 12 Nm torque spec for 2018, 2019, 2020, 2021, 2022, 2023, 2024
How to Replace Ignition Coils on a 2018 Honda Odyssey (Fix Misfire & Rough Idle)
Step-by-step ignition coil replacement with required tools, parts list, safety tips, and 12 Nm torque spec for 2018, 2019, 2020, 2021, 2022, 2023, 2024
🔧 Odyssey - Ignition Coil Replacement
Your Odyssey uses one ignition coil per cylinder (6 total). Replacing a weak coil can fix misfires, rough running, and flashing check-engine lights, and replacing all six at once can be good preventive maintenance if they’re aging.
Difficulty Level: Intermediate | Estimated Time: 1.5–2.5 hours
⚠️ Safety & Precautions
- ⚠️ Work on a cool engine; the exhaust and cylinder heads get very hot.
- ⚠️ Disconnect the negative battery cable to prevent accidental shorts.
- ⚠️ Pull on connectors (plastic housings), not the wires.
- ⚠️ If the check-engine light is flashing, avoid driving until repaired (catalyst damage risk).
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 1/4" drive ratchet
- 3" extension (1/4" drive)
- 6" extension (1/4" drive)
- Torque wrench (inch-pound or small Nm range)
- Flat-blade screwdriver
- Trim clip removal tool
- Needle-nose pliers
- Flashlight
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 6
- Dielectric grease - Qty: 1
📋 Before You Begin
- Park on level ground and shift to Park.
- Open the hood and let the engine cool completely.
- Use a 10mm socket to disconnect the negative battery cable and move it aside so it can’t spring back.
- Tip: Replace coils one-by-one to avoid mix-ups.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the engine cover (if equipped)
- Lift off the engine cover by releasing its mounting points (some pull straight up).
- If clips are present, use a trim clip removal tool to release them.
Step 2: Make room to access the coils
- Inspect the top of the engine for any intake ducting or brackets blocking coil access.
- Loosen intake duct clamps with a flat-blade screwdriver and reposition the duct if it blocks access.
- For any plastic push-clips, remove them with a trim clip removal tool.
Step 3: Unplug the first ignition coil connector
- Choose one coil and work on only that coil until it’s fully installed.
- Press the connector lock tab and pull the connector off the coil (use a flashlight to see the tab clearly).
- If it’s stubborn, gently help it with needle-nose pliers on the connector body (not the wires).
Step 4: Remove the ignition coil retaining bolt
- Remove the coil hold-down bolt using a 10mm socket with a 1/4" drive ratchet and 3" extension.
- Set the bolt aside where it won’t fall into the engine bay.
Step 5: Remove the ignition coil
- Twist the coil slightly, then pull it straight up to remove it from the spark plug tube.
- Check the coil boot (rubber end) for oil or coolant contamination.
- Tip: Oil in the tube needs diagnosis first.
Step 6: Install the new ignition coil
- Apply a very small amount of dielectric grease inside the new coil boot (a thin film only).
- Push the new coil straight down until it seats fully on the spark plug.
- Install the hold-down bolt by hand first to avoid cross-threading.
- Tighten the bolt with a torque wrench: Torque to 12 Nm (9 ft-lbs).
Step 7: Reconnect the coil electrical connector
- Push the connector on until it clicks/locks.
- Gently tug the connector to confirm it’s locked.
Step 8: Repeat for the remaining coils
- Repeat Steps 3–7 for each remaining coil.
- Use a 6" extension as needed for the coils that sit further back.
- Tip: Keep bolts with each coil location.
Step 9: Reinstall ducting/covers and reconnect the battery
- Reinstall any intake ducting and clips using the flat-blade screwdriver and trim clip removal tool.
- Reinstall the engine cover.
- Reconnect the negative battery cable using the 10mm socket.
✅ After Repair
- Start the engine and let it idle for 2–3 minutes. It should run smooth with no shaking.
- Test drive for 10–15 minutes and confirm no misfire symptoms.
- If the check-engine light stays on, the code may need to be cleared; use an OBD2 scan tool and recheck for returning misfire codes.
- If you found oil in any spark plug tube, stop and address that leak before it damages the new coil.
💰 DIY vs Shop Cost
Shop Cost: $450–$900 (parts + labor)
DIY Cost: $180–$600 (parts only)
You Save: $270–$300+ by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5–2.0 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.

















