Acura RSX Spark Plug Replacement Guide for 2002-2006 Models
Keep your K-series engine running strong by choosing the right spark plugs for your Base or Type-S model.
- For best performance and reliability, only use OEM brands NGK or Denso.
- Verify you have the correct part number for your Base or Type-S model, as they use different plugs.
- Always use a torque wrench set to 13 lb-ft to avoid costly damage to the cylinder head.
- Confirm the spark plug gap is 1.1mm (0.044 inches) before installation.
Symptoms of Failing Spark Plugs
When your RSX's spark plugs are nearing the end of their life, your car will give you several warning signs. Ignoring these can lead to worse fuel economy and potential damage to other components, like the catalytic converter.
- Rough Idle: The engine may shake or vibrate more than usual when stopped.
- Engine Misfires: You might feel a hesitation or stumble during acceleration. This can also trigger a flashing Check Engine Light.
- Poor Acceleration: The car feels sluggish and less responsive than normal.
- Reduced Fuel Economy: You'll find yourself filling up the gas tank more often. Worn plugs can decrease fuel economy by up to 30%.
- Difficulty Starting: The engine may take longer to turn over, especially in cold weather.
- Check Engine Light: Misfires will often log diagnostic trouble codes like P0300 (Random Misfire) or P0301-P0304 (Cylinder-specific Misfire).
Choosing the Right Aftermarket Spark Plugs
For the Acura RSX, the engine is sensitive to spark plug choice. While many brands are available, owner experiences overwhelmingly point to using the original equipment manufacturer (OEM) brands for the best reliability and performance.
Brand Quality Tiers for Acura RSX
Tier 1: OEM Brands (Highly Recommended)
- NGK & Denso: These are the original suppliers for Acura and are universally recommended by RSX owners. Iridium plugs from these brands, such as the NGK Laser Iridium or Denso Iridium Power, offer the best performance and longevity, often lasting up to 100,000 miles. They provide a strong spark perfect for the K-series VTEC engine.
Tier 2: Quality Aftermarket (Good Alternative)
- Bosch: Bosch Iridium spark plugs are a respectable alternative if NGK or Denso are unavailable. They are a well-known brand that produces quality ignition components. Some owners use them with good results.
Tier 3: Budget Brands (Use with Caution)
- Autolite & Champion: While these brands offer budget-friendly options, they are not recommended for the RSX. Forum discussions often contain reports of poor performance or premature failure with these brands in Honda/Acura engines. It's worth spending a little more for the peace of mind and performance of an OEM brand.
Base vs. Type-S: Use the Correct Plug!
The Base RSX (K20A3 engine) and the Type-S (K20A2/K20Z1 engine) use spark plugs with different heat ranges. Using the wrong plug can cause poor performance or even engine damage. Always verify the part number for your specific model.
- Base Model Plugs: NGK IZFR6K-11 or Denso SKJ20DR-M11
- Type-S Model Plugs: NGK IFR7G-11KS or Denso SK22PR-M11
Aftermarket Spark Plug Cost
| Category | Price Range (Set of 4) | Notes |
|---|---|---|
| New OEM (NGK/Denso) | $64 - $112 | The recommended choice for performance and longevity. |
| New Aftermarket | $15 - $88 | Price varies widely by brand and material (Copper, Platinum, Iridium). |
| Shop Labor | $61 - $90 | Typically a quick job for an experienced mechanic. |
Pro Tip: Installation Best Practices
Replacing the spark plugs on an RSX is a straightforward DIY job. Always use a torque wrench and tighten the new plugs to 13 lb-ft (18 N.m). Over-tightening can crack the plug or damage the engine's aluminum cylinder head, leading to very expensive repairs. Also, check that the gap is 1.1mm (0.044 inches) before installing. While many iridium plugs come pre-gapped, it's always wise to verify.
Frequently Asked Questions
How often should I change the spark plugs on my Acura RSX?
For the OEM-spec Iridium plugs, the recommended replacement interval is typically around every 100,000 - 110,000 miles. However, if you notice any symptoms of failure, you should inspect them sooner. Cheaper platinum or copper plugs will have a much shorter lifespan, sometimes as low as 30,000 miles.
What is the difference between Iridium and Platinum plugs?
Iridium is a harder, more durable material than platinum. This allows for a finer center electrode, which creates a more focused and consistent spark. For the RSX engine, iridium plugs provide better performance and have a significantly longer service life, making them worth the extra cost.
Do I really need a torque wrench?
Yes. The K-series engine has an aluminum cylinder head that can be easily damaged. Over-tightening a spark plug can strip the threads or cause a fracture, leading to a major repair. A torque wrench ensures the plug is seated correctly without causing damage. The correct torque is 13 lb-ft.
Are 'performance' spark plugs from other brands worth it?
Generally, no. The stock NGK and Denso iridium plugs are designed for high performance and are more than adequate for stock and even lightly modified RSX models. Sticking with the OEM brands is the safest and most reliable choice.
Helpful Videos
Technical Specifications
OEM Part Numbers: 9807B-5617W (Base - NGK IZFR6K11) 9807B-5615W (Base - Denso SKJ20DR-M11) 98079-571BV (Type-S - NGK IFR7G-11KS) 98079-571CV (Type-S - Denso SK22PR-M11S)
Socket Size: 5/8 inch (16mm). Spark Plug Gap: 1.1mm (0.044 inches). Torque Spec: 13 lb-ft (18 N.m).
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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