🔧 Odyssey - Spark Plug Replacement

On your Odyssey, the spark plugs ignite the air/fuel mixture. Replacing worn plugs helps prevent misfires, rough idle, poor fuel economy, and hard starting.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

Assumption: Stock ignition coils and OEM-style iridium plugs.

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⚠️ Safety & Precautions

• ⚠️ Work on a completely cool engine to avoid burns and thread damage.
• ⚠️ Keep dirt out of the cylinders; debris can damage the engine.
• ⚠️ If you disconnect the battery: use a 10mm wrench and remove the negative terminal first.
• ⚠️ Do not use anti-seize on Honda-style plated spark plug threads unless the plug maker specifically requires it.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• 10mm socket
• 10mm wrench
• Ratchet (3/8")
• Extension set (3/8", 3"-12")
• Wobble extension (3/8")
• Spark plug socket 5/8" (16mm) with rubber insert
• Torque wrench (3/8" drive, 10-30 ft-lbs range)
• Flathead screwdriver
• Phillips screwdriver
• Trim clip remover (specialty)
• Compressed air blow gun
• Flashlight

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OEM-style iridium) - Qty: 6
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, set the parking brake, and use wheel chocks.
• Open the hood and let the engine cool fully (at least 1 hour).
• Optional but safer: disconnect the battery negative terminal using a 10mm wrench.
• Set up good lighting; the rear bank plugs are tight to see.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Use a 10mm socket and ratchet to remove the engine cover fasteners.
• Lift the cover off and set it aside.

Step 2: Remove the air intake duct for access

• Use a flathead screwdriver (or appropriate driver) to loosen the intake hose clamps.
• Unclip/unbolt any intake snorkel pieces using a Phillips screwdriver or 10mm socket.
• Remove the ducting and set it aside so you can reach the front bank coils easily.
• Tip: Take a quick photo before removing hoses.

Step 3: Replace the front bank spark plugs (radiator side)

• On one coil at a time, press the lock tab and unplug the coil electrical connector by hand.
• Remove the coil hold-down bolt using a 10mm socket and ratchet.
• Twist the coil boot slightly, then pull the coil straight up and out.
• Blow out the spark plug well using compressed air blow gun to remove sand/dirt.
• Remove the spark plug using a 5/8" (16mm) spark plug socket, extension, and ratchet.
• Install the new plug by hand first (use the extension without the ratchet to avoid cross-threading).
• Tighten with a torque wrench: Torque to 18 Nm (13 ft-lbs).
• Apply a tiny amount of dielectric grease inside the coil boot (dielectric grease helps prevent moisture and sticking).
• Reinstall the coil and the 10mm bolt using a 10mm socket: Torque to 12 Nm (9 ft-lbs).
• Reconnect the coil electrical connector until it clicks.
• Repeat for the other two front bank plugs.

Step 4: Gain access to the rear bank (firewall side)

• Remove any plastic covers and wiring/hoses that block access by releasing clips with a trim clip remover (specialty) and loosening brackets with a 10mm socket.
• Use a flashlight to locate the three rear ignition coils.
• If space is too tight, remove the upper cowl trim fasteners using a trim clip remover (specialty) to improve hand room.
• Tip: A wobble extension helps in tight angles.

Step 5: Replace the rear bank spark plugs (firewall side)

• Unplug each coil connector by hand (press the lock tab first).
• Remove each coil hold-down bolt using a 10mm socket and ratchet.
• Remove the coil by twisting and pulling upward.
• Blow out each plug well using compressed air blow gun.
• Remove each plug using a spark plug socket 5/8" (16mm), wobble extension, and ratchet.
• Start each new plug by hand using the extension only.
• Tighten with a torque wrench: Torque to 18 Nm (13 ft-lbs).
• Add a small dab of dielectric grease inside each coil boot.
• Reinstall each coil and bolt: Torque to 12 Nm (9 ft-lbs) using a torque wrench.
• Reconnect each coil connector until it clicks.

Step 6: Reinstall intake parts and covers

• Reinstall the air intake ducting and clamps using a flathead screwdriver or Phillips screwdriver.
• Reinstall any brackets/clips you moved using a 10mm socket and trim clip remover (specialty).
• Reinstall the engine cover using a 10mm socket.
• If disconnected, reconnect the battery negative terminal using a 10mm wrench.

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✅ After Repair

• Start the engine and let it idle for 1-2 minutes; it should run smooth with no shaking.
• Listen for air leaks near the intake tube (a hissing sound) and tighten clamps with a flathead screwdriver if needed.
• Test drive 5-10 minutes and verify no check-engine light comes on.
• If a misfire light appears, recheck each coil connector is fully clicked in.

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💰 DIY vs Shop Cost

Shop Cost: $300-$650 (parts + labor)

DIY Cost: $60-$150 (parts only)

You Save: $240-$500 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 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.