You can change the spark plugs on a 2009 Honda Fit yourself. The process involves removing the coil-on-plug assemblies to access the four plugs, installing new plugs of the correct type, and tightening them to the manufacturer’s torque specification. Expect the job to take roughly 60–120 minutes depending on your experience and tools on hand.
What you need
Before you start, assemble the tools, parts, and safety gear listed below so you can complete the job without interruption.
- Four replacement spark plugs that match Honda’s specification for the 1.5L engine (often iridium or platinum types; copper plugs are not recommended for this engine).
- Spark plug socket (typically 5/8 inch) with a deep well, plus a long extension and a ratchet.
- Torque wrench capable of measuring in the low range (to about 18–22 Nm / 13–16 ft-lbs).
- Ratchet, 6–10 inch extension, and a universal joint if needed for reach.
- Flat-head and/or Phillips screwdrivers or appropriate tools to remove the engine cover.
- Dielectric grease for electrical connectors to help protect the coil boots.
- Anti-seize lubricant (generally not recommended by Honda for newer plugs; consult your manual).
- Owner’s manual or service manual for your exact plug type and gap specification.
- Safety gear: gloves and eye protection.
Note: Always use the spark plugs specified by Honda for your engine model and market region. The 2009 Fit typically uses long-life iridium or platinum plugs; verify the exact part number and gap before purchasing.
Step-by-step guide
The following steps outline a typical replacement for a 2009 Honda Fit with a coil-on-plug ignition system. Work methodically and recheck each connection as you go.
- Park the car on a flat surface, set the parking brake, and disconnect the negative battery terminal to prevent accidental shorting while you work.
- Remove the engine cover if your model has one, using the appropriate screws or clips.
- Identify the coil-on-plug assemblies for each cylinder. Starting with one, disconnect the electrical connector attached to the coil boot, then remove the small retaining bolt if present and lift the coil straight up and out of its well.
- Using the spark plug socket, extension, and ratchet, carefully reach down into the plug well and turn counterclockwise to loosen and remove the old spark plug. If a plug is stubborn, apply a gentle rocking motion rather than forcing it straight out.
- Inspect the old plug for wear and deposits; replace if worn, fouled, or if the vehicle has reached the recommended replacement interval. If needed, check or adjust the gap on the new plug according to the service manual (typical gap for many Hondas is in the 0.043–0.047 inch range, but confirm for your exact plug type).
- Install the new spark plug by threading it in by hand to avoid cross-threading, then tighten to the specified torque (generally in the 13–16 ft-lbs / 18–22 Nm range for this engine). Do not overtighten.
- Reinstall the ignition coil onto the plug, secure it with the bolt if applicable, and reconnect the electrical connector. Repeat for all four cylinders.
- Once all plugs and coils are reseated, reinstall the engine cover (and any removed fasteners), reconnect the negative battery terminal, and secure all tools and components.
- Start the engine to confirm a smooth idle and listen for any misfire or rough-running symptoms. If something sounds off, recheck coil connections and plug seating.
After finishing, it’s a good idea to drive the car briefly to ensure smooth operation and monitor for any fault codes that might indicate a misfire or coil issue.
Choosing the right plugs
Understanding plug types and how they affect maintenance helps ensure longevity and performance between changes.
Plug types explained
The 2009 Honda Fit typically uses long-life iridium or platinum plugs in the factory install. These plugs offer extended service intervals compared with copper plugs, which wear out faster. Always replace with the plug type Honda specifies for your engine code and market region to maintain performance and reliability.
New plugs are often pre-gapped, but if you receive plugs that require gap adjustment, set them to the specification found in your service manual before installation. Do not mix plug types or heat ranges beyond what Honda recommends.
Gap and torque guidelines
Typical gap for this engine range is approximately 0.043–0.047 inches, but verify the exact value for your plug model in the owner’s manual or service bulletin. Tightening torque generally falls in the 13–16 ft-lbs (18–22 Nm) range; use a torque wrench to ensure you reach but do not exceed the specified torque.
Important: Do not use anti-seize on spark plug threads in modern engines unless the manufacturer advises otherwise. For most Honda applications, a light coat on the threads is not recommended and can affect the specified torque.
Safety and troubleshooting
Keep these safety tips in mind to avoid injury and damage to your vehicle.
- Work with the engine cool to minimize burn risk and to prevent disturbing hot components.
- Handle ignition coils and electrical connectors gently to avoid damaging the wiring harness or coil boots.
- If you notice damaged coil boots, cracked wiring, or corrosion, replace the affected coil pack or connectors.
- If the Check Engine Light returns after replacement, use an OBD-II scanner to check for misfire codes or have a mechanic diagnose the issue.
If you’re uncertain at any point or the engine shows persistent misfires, seek professional assistance to avoid risking damage to the engine or ignition system.
Summary
Changing spark plugs on a 2009 Honda Fit is a straightforward DIY task for a handy hobbyist. It requires removing the coil-on-plug assemblies, installing four correctly specified plugs, and torquing them to the manufacturer’s specification. With the right tools, careful handling of the ignition components, and adherence to the Honda-recommended plug type and gap, you can maintain efficient combustion, reliable starts, and smooth operation between service intervals. Always consult the official service manual or a qualified technician for the exact specifications for your vehicle’s engine and market.
How often should spark plugs be changed on a Honda Fit?
about every 30,000 miles
To keep your Honda vehicle's ignition system working its best, experts recommend changing your spark plugs about every 30,000 miles.
How much does it cost to replace spark plugs in a 2009 Honda Fit?
between $198 and $346
The average cost for a 2009 Honda Fit Spark Plug Replacement is between $198 and $346. Labor costs are estimated between $110 and $161 while parts are priced between $88 and $185. This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.
What kills spark plugs quickly?
Pre-ignition can lead to heat building up in the combustion chamber causing the spark plugs to fail. In addition, if the cooling system isn't functioning correctly, it can cause the engine and spark plugs to overheat. This overheating can lead to the spark plug's electrode wearing out faster.
Can I replace my spark plugs by myself?
Replacing worn spark plugs can greatly improve your engine's performance and efficiency, and it can be done at home with basic hand tools.