A Guide to Aftermarket Spark Plugs for the 2019-2024 Lexus IS350
Keep your IS350's 3.5L V6 engine running at its peak with the right set of new spark plugs.
- Stick to OEM-equivalent Iridium spark plugs from Denso or NGK for best performance and reliability.
- The recommended replacement interval is every 60,000 miles.
- Replacement is moderately difficult due to the need to remove the intake plenum to access the rear three plugs.
- Symptoms of failure include rough idle, poor acceleration, reduced fuel economy, and a check engine light with misfire codes.
Signs of Failing Spark Plugs in Your IS350
When your spark plugs start to wear out, your Lexus will likely give you a few warning signs. Ignoring them can lead to reduced performance, worse fuel economy, and potentially more expensive repairs down the road. Be aware of symptoms like a rough idle, engine hesitation during acceleration, or a noticeable drop in gas mileage. A check engine light, especially with codes related to engine misfires (P0300-P0306), is a strong indicator of a spark plug problem.
Choosing the Right Aftermarket Spark Plug
For your 2019-2024 Lexus IS350, the factory-installed spark plugs are typically high-quality Iridium units made by either Denso or NGK. These two brands are the original equipment (OEM) suppliers for Toyota and Lexus, making them the most recommended choice for replacement.
Aftermarket Brand Quality Tiers for Lexus IS350
| Tier | Brands | Honest Assessment |
|---|---|---|
| OEM-Equivalent | Denso, NGK | These are the brands Lexus uses from the factory. Choosing their Iridium options ensures you get the same performance, longevity, and reliability as the original parts. Most owners and mechanics strongly recommend sticking with these brands. |
| Reputable Aftermarket | Bosch | Bosch offers Iridium spark plugs that are a viable alternative. They are a well-respected brand in the auto parts industry, though Denso and NGK remain the top choice for most Lexus specialists. |
| Budget-Friendly | Autolite, Champion | While these brands offer Iridium plugs at a lower price, they are generally not recommended for the IS350's sophisticated engine. Forum discussions among Lexus owners often advise against using budget brands, as the cost savings may not be worth the potential risk of reduced performance or shorter service life. It's critical to ensure the plug has the correct length (reach) and heat range; some budget options may have fitment issues. |
Known Issues, Recalls, and TSBs
Searches for the 2019-2024 Lexus IS350 did not reveal any specific recalls or Technical Service Bulletins (TSBs) directly related to spark plugs. However, there have been recalls for fuel pumps on these models, which can cause stalling and misfire-like symptoms. If you are experiencing engine problems, it's wise to check for any open recalls on your vehicle.
A Note on Spark Plug Gap
OEM-equivalent Iridium spark plugs from Denso and NGK typically come pre-gapped from the factory for your specific vehicle. It is highly recommended not to attempt to adjust the gap on these fine-wire Iridium plugs, as you can easily damage the delicate center electrode. Always verify the part number is correct for your IS350 to ensure the pre-set gap is accurate.
Cost to Replace Spark Plugs on a 2019-2024 Lexus IS350
| Cost Category | Estimated Price Range |
|---|---|
| Aftermarket Spark Plugs (Per Plug) | $4.09 - $33.37 |
| OEM Spark Plugs (Per Plug) | $15 - $32 |
| Shop Labor Cost | $269 - $395 |
| Total Professional Replacement | $386 - $511+ |
Pro Tip: Replacing Ignition Coils
While not a required maintenance item, some owners choose to replace the ignition coils at the same time as the spark plugs, especially on higher-mileage vehicles. The ignition coils sit directly on top of the spark plugs, so there is no additional labor cost to replace them during a spark plug job. If one coil has failed, it may be wise to replace them all as a preventative measure.
Frequently Asked Questions (FAQ)
How often should I replace the spark plugs on my Lexus IS350?
The recommended replacement interval for the spark plugs on a Lexus IS350 is typically every 60,000 miles. This ensures the engine continues to operate efficiently and prevents wear-related issues.
Is it difficult to replace the spark plugs myself?
The difficulty is moderate. The front three spark plugs (passenger side) are relatively easy to access. However, the rear three plugs (driver's side) are located under the intake plenum, which requires removal for access, making the job more complex and time-consuming. If you are not an experienced DIYer, it might be best to leave this job to a professional.
Should I use anti-seize on the new spark plug threads?
Most modern NGK and Denso spark plugs have a special nickel plating on the threads that acts as an anti-seize agent. Applying additional anti-seize can lead to over-torquing the plugs, which can damage them or the engine's cylinder head. It is generally recommended to install them dry, following the manufacturer's torque specifications.
What's the difference between Iridium and Platinum plugs?
Iridium is a harder and more durable material than platinum. Iridium spark plugs, like those specified for your IS350, have a very fine-wire center electrode that requires less voltage to create a spark. This leads to a more efficient and powerful spark, better fuel economy, and a longer service life compared to platinum or copper plugs.
Helpful Videos
Technical Specifications
OEM Part Numbers: 90919-01263 90919-01249 FK20HBR8
The 2019-2024 Lexus IS350 requires Iridium-type spark plugs. The OEM plugs are typically supplied by Denso or NGK. These plugs come pre-gapped, and the gap should not be adjusted. The correct torque specification during installation is critical to avoid damage.
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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.
- Lexus IS350:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Signs of Failing Spark Plugs in Your IS350
- Choosing the Right Aftermarket Spark Plug
- Aftermarket Brand Quality Tiers for Lexus IS350
- Known Issues, Recalls, and TSBs
- A Note on Spark Plug Gap
- Cost to Replace Spark Plugs on a 2019-2024 Lexus IS350
- Pro Tip: Replacing Ignition Coils
- Frequently Asked Questions (FAQ)
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