How to Replace Your 2023 Honda Odyssey 3.5L Spark Plugs — DIY Guide

Here's what I do every time I service the 2023 Honda Odyssey 3.5L — and this is a job worth doing yourself because dealers charge $250–$350 for a spark plug replacement on the J35Y8 V6. DIY cost is around $60–$80 for quality iridium plugs. The Odyssey's 3.5L is a transversely-mounted V6, which means the three front plugs are easy, and the three rear plugs require a little patience — but no specialty tools beyond a 3/8-inch extension.

---

Parts & Tools

Item	OEM / Spec	Detail
Spark plugs (6)	NGK ILFR6B-11 (Honda 12290-RCA-A01)	Iridium, pre-gapped at 0.044 in
Plug gap	0.044 in (1.1 mm)	Factory spec; do not re-gap iridium
Torque spec	13 lb-ft (18 Nm)	Into aluminum head — do not overtorque
Plug type	14mm, 5/8-inch hex	3/8-drive extension needed for rear bank

Additional tools: 3/8-inch ratchet, 5/8-inch spark plug socket (with rubber insert), 3-, 6-, and 10-inch extensions, universal swivel joint, dielectric grease.

Plug note: Honda OE plugs for the Odyssey are NGK iridium — the 12290-RCA-A01 is the factory part number. NGK ILFR6B-11 is the aftermarket equivalent. Denso SK20HR11 is the Denso equivalent. Do NOT use copper plugs — the J35 V6 requires iridium for the advertised 60,000-mile service interval. Do not re-gap iridium plugs.

---

DIY vs. Shop Cost

Item	DIY Cost	Shop Cost
NGK ILFR6B-11 × 6 plugs	$48–$72	—
Dielectric grease (tube)	$4–$6	—
Total parts	~$52–$78	—
Labor	$0	$180–$250
Total	~$52–$78	$250–$340

---

Step-by-Step Spark Plug Replacement

1. Let the Engine Cool Completely

Wait at least 2 hours after last use. Hot plugs can seize in aluminum heads.

2. Remove Engine Covers

The 2023 Odyssey has a plastic engine cover over the top of the J35Y8. It lifts straight up and clips off — no tools needed.

3. Front Bank (Cylinders 1, 3, 5)

The front three plugs face you directly on the front of the engine:

• Pull the ignition coil connector off each coil (press the tab and pull)
• Remove the single 10mm bolt holding each coil bracket
• Pull the coil straight up — it will take some force on the first removal
• Use a 5/8-inch plug socket with a 6-inch extension to break each plug loose counterclockwise
• Install the new NGK ILFR6B-11 by hand first, then torque to 13 lb-ft (18 Nm)
• Apply a thin film of dielectric grease to the inside of the coil boot before reinstalling

4. Rear Bank (Cylinders 2, 4, 6)

The rear three plugs are between the engine and the firewall:

• Disconnect each rear coil connector; remove the 10mm coil bolt
• Use a 10-inch plus 3-inch extension combination with a swivel joint to reach the plug holes at an angle
• Break each plug loose counterclockwise; use the rubber-insert socket to hold the plug during removal
• Install new plugs by hand first to avoid cross-threading
• Torque to 13 lb-ft (18 Nm) using a torque wrench with the extension

5. Reinstall Coils and Reconnect Harnesses

Push each coil boot fully onto the new plug — you should feel a soft click. Reinstall the 10mm coil bolt. Reconnect each ignition coil connector.

6. Reinstall the Engine Cover

Press down until all four clips seat.

7. Start and Verify

Crank the engine — it should start cleanly. Any misfire will show as a rough idle or flashing Check Engine light. Clear stored codes after a clean start.

---

Odyssey 3.5L V6 Spark Plug Notes

1. Check the plug wells for oil: If you pull a coil and see oil pooled in the plug well, the valve cover gasket is leaking. Replace valve cover gaskets before the oil reaches plug threads.
2. Plug condition tells a story: Grayish-white center electrode = normal. Oily deposits = oil consumption. Black soot = rich running or short-trip buildup.
3. 60,000-mile interval: Don't push iridium plugs to 90,000+. Worn plugs put extra load on the ignition coils.

For related Honda maintenance guides, see the Honda oil change overview at /guides/oil-changes and our maintenance schedule guide at /guides/maintenance-schedules.

---

Want step-by-step guides for every repair on your Honda? OwnerDrop has 28+ guides starting at $29.99/mo — see all plans at /pricing.