🔧 Ignition Coils - Replacement

Replacing the ignition coils on your Sequoia is straightforward because the coils sit on top of the valve covers. If you have a misfire, rough idle, or flashing check engine light, fresh coils can restore smooth running and prevent damage from continued misfiring.

Difficulty Level: Beginner | Estimated Time: 1-2 hours

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⚠️ Safety & Precautions

• Ignition coils carry high voltage. Do not touch coil connectors with the engine running.
• Let the engine cool fully before starting. Hot intake parts and valve covers can burn you.
• Disconnect the negative battery terminal before removing coils.
• Keep dirt out of the spark plug wells. Debris can damage the plugs or coils.
• If your check engine light is flashing, avoid driving until the repair is complete.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4-inch ratchet
• 1/4-inch extension
• Torque wrench
• Flat trim tool
• Needle-nose pliers
• Dielectric grease
• Safety glasses
• Nitrile gloves
• Battery terminal wrench

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil set - Replace all 8 - Qty: 8

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the engine cool completely.
• Save radio presets if needed before disconnecting the battery.
• Disconnect the negative battery terminal with a 10mm socket.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect power

• Use a 10mm socket to remove the negative battery cable.
• Move the cable aside so it cannot touch the terminal.

Step 2: Remove the engine cover and intake ducting

• Use a flat trim tool to carefully lift off the engine cover.
• If the intake tube blocks access, loosen its clamps with the correct socket/driver and remove the duct.
• Keep hardware organized.

Step 3: Locate the ignition coils

• The coils sit directly on top of the spark plugs, one coil per cylinder.
• Work on one side at a time so you do not mix up connectors.

Step 4: Unplug the coil connector

• Press the connector lock and pull the electrical connector straight off by hand.
• If the connector is stuck, use needle-nose pliers gently on the release tab area, not the wires.

Step 5: Remove the coil

• Use a 10mm socket and 1/4-inch ratchet to remove the coil hold-down bolt.
• Pull the coil straight up and out of the spark plug well.
• If it resists, twist it slightly while pulling upward.

Step 6: Install the new coil

• Compare the new coil to the old one to confirm it matches.
• Apply a small amount of dielectric grease inside the boot of the new coil.
• Push the coil straight down onto the spark plug until fully seated.
• Install the hold-down bolt and tighten with a torque wrench to 7 N·m (62 in-lbs).

Step 7: Reconnect the electrical connector

• Push the connector on until it clicks.
• Make sure the connector lock is fully engaged.

Step 8: Repeat for the remaining coils

• Replace all 8 coils if you are doing a full refresh.
• Do one coil at a time to avoid mix-ups.

Step 9: Reinstall removed parts and restore power

• Reinstall the intake ducting and engine cover.
• Reconnect the negative battery cable with a 10mm socket.

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✅ After Repair

• Start the engine and listen for smooth idle.
• Check that the check engine light is off.
• If you have a scan tool, clear misfire codes and verify there are no pending faults.
• Test drive gently and confirm there is no hesitation or shaking.

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💰 DIY vs Shop Cost

Shop Cost: $650-$1,200 (parts + labor)

DIY Cost: $160-$400 (parts only)

You Save: $490-$800 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1-2 hours.

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🎯 Ready to get started?

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