Choosing the Right Spark Plugs for Your 1992-1997 Subaru SVX
Keep your unique EG33 engine firing on all six cylinders with the correct plugs.
- Due to the difficult installation on the SVX's EG33 engine, use high-quality Iridium or Platinum spark plugs from NGK or Denso to extend the replacement interval.
- The OEM spark plug is an NGK Platinum plug, part number PFR6B-11 (Subaru part number 22401AA370).
- Symptoms of failure include rough idle, poor acceleration, reduced gas mileage, and a check engine light for misfires (P0300-P0306).
- Accessing the spark plugs requires removing the air intake box and the battery; the driver's side rear plug is the most difficult to reach.
Signs of Failing Spark Plugs in Your SVX
Worn-out spark plugs can cause several noticeable problems. If you experience any of these, it might be time for a replacement. Common symptoms include a rough idle, where the car shakes or vibrates when stopped. 🎬 Watch: Diagnosing common causes of a rough engine idle. You might also notice sluggish acceleration, a decrease in fuel economy, or difficulty starting the engine. A check engine light, especially with codes indicating an engine misfire (P0300-P0306), is a strong sign of a spark plug issue.
Choosing the Right Aftermarket Spark Plugs
When replacing spark plugs on your SVX, quality matters. The job is labor-intensive, so it's best to use plugs that will last. The original equipment (OEM) plugs for the SVX were made by NGK. Aftermarket options from reputable brands can meet or exceed OEM quality.
Brand Quality Tiers for Subaru SVX
| Tier | Brands | Description |
|---|---|---|
| Top Tier (OEM equivalent or better) | NGK, Denso | NGK is the original manufacturer for Subaru and the most recommended brand by owners and mechanics. Denso is another high-quality Japanese brand often used as OEM in other vehicles and offers excellent performance and durability. Using Iridium plugs from these brands, like NGK Iridium IX, 🎬 See this guide for expert Subaru spark plug tips. can offer a longer service life and improved performance. |
| Mid-Tier | Champion, Autolite | These brands offer reliable, standard-replacement plugs. While they may not have the longevity of iridium plugs, they are a cost-effective option that performs well. Some owners have noted that while functional, the quality control might not be as consistent as top-tier brands. |
| Economy Tier | Skyward, other store brands | These are the most affordable options. They will function, but their lifespan and performance may be less than higher-priced alternatives. Given the difficulty of changing the plugs on an SVX, investing in a longer-lasting plug is often recommended to avoid doing the job more frequently. |
A Note on Installation Difficulty
Replacing the spark plugs on the Subaru SVX's EG33 engine is a challenging task. Access to the plugs, especially the rearmost one on the driver's side, is very tight due to the engine's position in the bay. To gain access, you typically need to remove the air filter assembly and the battery. Because of the labor involved, many owners choose high-quality platinum or iridium plugs to maximize the time between changes.
🎬 Watch: A step-by-step walkthrough of the SVX spark plug change.Frequently Asked Questions (FAQ)
How often should I change the spark plugs on my SVX?
For older vehicles like the 1992-1997 SVX, the replacement interval depends on the type of plug used. Standard copper plugs may need changing every 30,000 miles. However, due to the difficult installation, most owners opt for longer-lasting platinum or iridium plugs, which can last 60,000 miles or more. Always check your owner's manual for specific recommendations.
Are iridium or platinum plugs worth the extra cost for my SVX?
Yes, for the SVX, they are generally considered a worthwhile investment. The primary benefit is longevity. Since the labor to change the plugs is significant, using a plug that lasts twice as long means you won't have to perform this difficult job as often. They also provide excellent performance and ignitability.
What is the correct OEM spark plug for my SVX?
The genuine Subaru part number is 22401AA370, which corresponds to the NGK model PFR6B-11. This is a platinum plug and was the original equipment for the vehicle. Using this plug or an equivalent aftermarket Iridium version from NGK or Denso is highly recommended.
Can I replace just one bad spark plug?
While you can, it is strongly recommended to replace all six spark plugs at the same time. Spark plugs wear out at a similar rate. If one has failed, the others are likely near the end of their service life. Changing all of them at once ensures consistent performance and saves you from having to repeat the labor-intensive job again soon.
Helpful Videos
Technical Specifications
OEM Part Numbers: 22401AA370
The OEM plug is the NGK PFR6B-11. This is a platinum plug with a 14mm thread size, 26.5mm reach, and a 16mm (5/8") hex size. It is a resistor-type plug with a flat seat.
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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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