How to Replace Ignition Coils on a 2012 Toyota Tacoma (Fix Misfire & Rough Idle)
Step-by-step coil-on-plug replacement with required tools, parts list, torque specs, and safety tips for 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015
How to Replace Ignition Coils on a 2012 Toyota Tacoma (Fix Misfire & Rough Idle)
Step-by-step coil-on-plug replacement with required tools, parts list, torque specs, and safety tips for 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015
🔧 Tacoma - Ignition Coil Replacement
Your Tacoma uses a coil-on-plug system (one ignition coil per spark plug). Replacing a bad coil restores a strong spark and usually fixes a misfire, rough idle, or flashing check engine light.
Difficulty Level: Intermediate | Estimated Time: 1.0-2.5 hours
⚠️ Safety & Precautions
- ⚠️ Work on a cool engine to avoid burns.
- ⚠️ Disconnect the negative battery cable to prevent accidental shorts and to protect electronics.
- ⚠️ Don’t pull on wiring; unplug connectors by pressing the lock tab first.
- ⚠️ If you remove the intake manifold, keep dirt out of the intake ports at all times.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 3/8" ratchet
- 6" extension
- 12" extension
- 3/8" universal joint swivel
- Torque wrench (inch-pound)
- Torque wrench (foot-pound)
- Flat-blade screwdriver
- Needle-nose pliers
- Trim clip removal tool
- Shop flashlight
- Magnetic pickup tool
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 1-6
- Dielectric grease - Qty: 1
- Upper intake manifold gasket set - Qty: 1 (only if intake is removed)
- Throttle body gasket - Qty: 1 (only if throttle body is removed)
- Spark plugs - Qty: 6 (optional, if due)
📋 Before You Begin
- Park on level ground, transmission in neutral, and set the parking brake.
- Let the engine cool completely.
- Disconnect the negative battery cable using a 10mm socket. Tuck it so it can’t spring back.
- Tip: Label coils 1–6 with tape.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the engine cover (if equipped)
- Remove the cover fasteners using a 10mm socket, then lift the cover off.
Step 2: Open up access to the coils
- Loosen the intake tube clamps using a flat-blade screwdriver.
- Unclip/remove any plastic retainers using a trim clip removal tool.
- Move the intake tube/ducting out of the way enough to reach the coils (especially near the firewall).
Step 3: Unplug the ignition coil electrical connector
- Press the connector lock tab and pull the connector straight off by hand.
- If the lock tab is stubborn, gently assist with a flat-blade screwdriver (do not break the tab).
Step 4: Remove the coil hold-down bolt
- Remove the coil bolt using a 10mm socket with a 6" extension.
- Use a magnetic pickup tool if the bolt is hard to grab.
Step 5: Remove the ignition coil
- Twist the coil slightly to break the seal, then pull it straight up and out by hand.
- Tip: A gentle twist works better than yanking.
Step 6: Install the new ignition coil
- Apply a small smear of dielectric grease inside the rubber boot (dielectric grease is a non-conductive grease that helps prevent moisture and makes future removal easier).
- Push the coil straight down onto the spark plug until it fully seats.
- Install the coil hold-down bolt using a 10mm socket, then Torque to 9 Nm (80 in-lbs) using a torque wrench (inch-pound).
Step 7: Reconnect the electrical connector
- Push the connector on until it clicks (by hand).
- Gently tug to confirm it’s locked.
Step 8: Repeat for remaining coils
- Repeat Steps 3–7 for any other coil(s) you’re replacing.
- If you’re chasing a misfire, you can swap a suspected coil to another cylinder and see if the misfire “moves” (requires a scan tool to confirm).
Step 9: If you cannot physically reach the rear coils (tight access option)
- Remove additional intake components for room using a 10mm socket, 12" extension, and 3/8" universal joint swivel.
- If the throttle body is removed, reinstall fasteners and Torque to 10 Nm (89 in-lbs) using a torque wrench (inch-pound).
- If the upper intake manifold is removed, replace the gaskets and reinstall fasteners evenly, then Torque to 21 Nm (15 ft-lbs) using a torque wrench (foot-pound).
- Important: Cover any exposed intake openings immediately and keep debris out.
Step 10: Reassemble intake tubing and covers
- Reinstall the intake tube and tighten clamps using a flat-blade screwdriver.
- Reinstall the engine cover using a 10mm socket.
Step 11: Reconnect the battery
- Reconnect the negative battery cable using a 10mm socket.
✅ After Repair
- Start the engine and let it idle. It should run smoothly with no shaking.
- If you had a check engine light, clear codes with a scan tool and confirm the misfire does not return.
- Test drive 10–15 minutes and recheck for warning lights.
- Recheck that all coil connectors are fully clicked in and intake clamps are tight.
💰 DIY vs Shop Cost
Shop Cost: $250-$750 (parts + labor, depends on number of coils)
DIY Cost: $60-$450 (parts only, depends on number of coils)
You Save: $190-$300+ by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-2.0 hours.
🎯 Ready to get started?
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