10 Best Ignition Coil For Subaru STI Tested 2025

I remember the first time my STI started suffering from a rough idle—it felt sluggish, hesitant under boost, and the dreaded P0300 code flashed up. When you’re running the EJ257 engine, especially if it’s modified, ignition reliability isn’t just a suggestion, it’s mandatory. I’ve personally sorted through the top options to find what truly performs. This comprehensive guide details the best ignition coil for subaru sti models, focusing on reliable spark energy, longevity, and overall value, whether you’re running stock boost or pushing big turbo numbers.

IMAGE	PRODUCT NAME	AMAZON LINK
	Mishimoto Ignition Coil 4-Pack compatible with Subaru…	View on Amazon
	Subaru 2004-2010 Forester XT WRX STi Legacy GT Turbo…	View on Amazon
	TRQ Ignition Coil Set Compatible with 2011-2013 Subaru…	View on Amazon
	DrCax OEM Ignition Coil UF665 22433AA602 Compatible with…	View on Amazon
	TAUTOY Set Of 4 UF738 UF665 Ignition Coil Pack (2.5L…	View on Amazon
	Mishimoto Ignition Coil Compatible With Subaru WRX/STi 2.5L…	View on Amazon
	Mishimoto Ignition Coil Compatible With Subaru WRX/STi 2.5L…	View on Amazon
	Subaru Ignition Coils Forester XT Wrx Sti Legacy Gt…	View on Amazon
	PHILTOP Set of 4 Ignition Coil Pack and Iridium Spark…	View on Amazon
	SYKRSS 4-Pack UF665 Ignition Coils Compatible with Subaru…	View on Amazon

Mishimoto Ignition Coil 4-Pack compatible with Subaru WRX/STI 2004-2010

If you own a classic GD or GR chassis STI (2004–2010) and are looking for a reliable, performance-focused replacement, the Mishimoto 4-pack is an excellent choice. These coils are designed to seamlessly integrate into your older EJ engine bay, immediately refreshing your ignition system. They are specifically engineered to meet or exceed OEM specifications, ensuring that both stock and mildly modified vehicles receive a strong, consistent spark, eliminating those annoying misfires under load and improving overall startup quality.

Key features that stand out:
– Direct fit for 2004-2010 Subaru WRX STI engines.
– Improves engine startup, idle, and restores performance.
– Mishimoto Lifetime Warranty provides great peace of mind.

Pros:
– Excellent performance for EJ257 engines, even with light tuning.
– Direct-fit installation simplifies the replacement process.
– Backed by Mishimoto’s renowned warranty.

Cons:
– Specifically limited to the older 2004-2010 generation.

Best for: EJ257 owners (04-10) seeking a high-quality, long-term replacement that supports performance mods.

Expert Opinion: Mishimoto excels at engineering parts that improve upon the factory design while maintaining direct compatibility. These coils are a notable step up in reliability compared to aging stock units in classic STIs.

Subaru 2004-2010 Forester XT WRX STi Legacy GT Turbo Ignition Coils set of 4-22433AA542 – Genuine OEM

For the purist who demands absolute factory quality, this Genuine OEM set is the definitive option for 2004–2010 STI models. When searching for the best ignition coil for subaru sti reliability, going genuine often removes any guesswork, especially regarding tuning consistency. These are the coils your car came with, ensuring perfect integration with your vehicle’s factory ECU and providing the trusted performance Subaru intended.

Key features that stand out:
– Genuine Subaru Part Number: 22433AA542 x4.
– Ensures 100% factory compatibility and reliability.
– Ideal replacement for maintaining stock performance.

Pros:
– Highest guaranteed compatibility and fitment.
– Known long-term reliability for stock boost levels.
– The standard for consistency in the EJ platform.

Cons:
– Tends to be pricier than aftermarket alternatives.

Best for: Stock STIs (04-10) or owners prioritizing OE reliability above all else.

Expert Opinion: While aftermarket options offer enhanced features, nothing beats genuine Subaru parts for maintaining the vehicle’s original integrity and guaranteed compatibility, especially critical in the sensitive turbo ignition system.

TRQ Ignition Coil Set Compatible with 2011-2013 Subaru Forester 2011-2014 Impreza 2010-2012 Legacy 2015-2020 WRX STI

The TRQ ignition coil set provides a budget-friendly yet reputable option for newer STI models (2015–2020) and compatible turbo Subarus. TRQ is established in the replacement parts sector, focusing on manufacturing direct-fit components that save time and effort during installation. This set is a full replacement kit designed to match the form and function of the original equipment, eliminating the need for modifications and quickly resolving common misfire issues.

Key features that stand out:
– Kit Includes (4) Ignition Coils for a complete replacement.
– Direct replacements for the original equipment, ensuring precise fit.
– TRQ is a premium choice provider with over 25 years of experience.

Pros:
– Very easy installation due to precise, direct-fit design.
– Excellent value for money compared to high-end brands.
– Wide compatibility across modern Subaru turbo platforms.

Cons:
– Long-term reliability under heavy tuning is unproven compared to performance brands.

Best for: Owners of newer STIs (2015+) looking for a dependable, cost-effective replacement set to address misfires.

Expert Opinion: If your 2015+ STI is stock or lightly modified and you need an affordable solution fast, TRQ provides the necessary OE-spec compliance without the OEM price tag.

DrCax OEM Ignition Coil UF665 22433AA602 Compatible with Subaru Forester 2011-2013 Impreza 2011-2014 Legacy 2010-2012 WRX 2013-2014 WRX STI 2.5L H4-1 Pack

Sometimes you only need to replace one failing coil, and the DrCax unit is perfect for that job. This single-pack coil is engineered to the OE standard, making it an ideal choice for diagnosing and fixing specific cylinder misfires (P030X codes). It is built to achieve or exceed OE specifications and focuses specifically on resolving common issues like stalling, engine jerking, and poor idling, restoring peak engine performance without requiring a full set replacement.

Key features that stand out:
– Built to achieve or exceed OE specifications subject to strict quality control.
– Fixes common ignition system failures such as backfiring and stalling.
– Includes a one-year after-sales service guarantee.

Pros:
– Highly effective at fixing specific ignition system malfunctions.
– Cost-effective solution if only one coil is faulty.
– Matches common OE replacement numbers (UF665).

Cons:
– Buying a single coil can be risky if other coils are near failure.

Best for: Diagnosing and replacing a single faulty coil in the 2013-2018 STI generation.

Expert Opinion: While it’s always best practice to replace coils in sets, this single DrCax unit offers great value and high quality for those who have definitively isolated a single failing coil.

TAUTOY Set Of 4 UF738 UF665 Ignition Coil Pack (2.5L Only) For Subaru Forester Impreza 2011-2013,Legacy 2010-2012,WRX 2012-2013,WRX STI 2015-2017, Replace # 22433AA600 22433AA601 5C2100 C884

TAUTOY offers a high-performance, budget-conscious coil set for the 2.5L turbo engine found in mid-generation STIs. Emphasizing premium construction, these coils utilize high conductive copper wire and high dielectric performance epoxy. This ensures excellent connectivity and corrosion resistance, leading to a long service life. They are manufactured in TS16949 certified facilities, meaning they adhere to stringent quality control standards for spark energy output and durability, making them a reliable alternative to OEM.

Key features that stand out:
– Utilizes High conductive copper wire and high dielectric performance epoxy.
– Engineered and tested to match or exceed OE for spark energy output.
– Manufactured in TS16949 certified facilities.

Pros:
– Excellent quality materials enhance durability and service life.
– Rigorous testing ensures consistency and reduces failure rates.
– Great fitment across multiple 2.5L turbo models.

Cons:
– Brand recognition is lower than performance giants like Mishimoto.

Best for: STI owners (2015-2017 generation) seeking tested quality without paying the high price of premium aftermarket brands.

Expert Opinion: The use of high-quality components and certification (TS16949) means this set is a strong contender for the best ignition coil for subaru sti when balancing quality and cost is important.

Mishimoto Ignition Coil Compatible With Subaru WRX/STi 2.5L 2011+, Set of 4

Mishimoto doubles down on the newer STI platform with this dedicated set for the 2011+ WRX/STi 2.5L engines. If your VA-chassis STI is running a custom tune or pushing higher-than-stock boost levels, you need ignition components that won’t fail under pressure. This 4-pack ensures a strong, reliable spark across the entire RPM range, significantly improving overall engine response and making it a top choice when upgrading the best ignition coil for subaru sti performance.

Key features that stand out:
– Direct fit for 2011+ WRX/STi 2.5L.
– Designed and tested to meet or exceed OEM Subaru performance specifications.
– Refreshes the ignition system for stock and modified vehicles.

Pros:
– Enhanced performance and reliability for tuned engines.
– Improves rough idle and ensures quick, reliable starts.
– Comes as a full set for a comprehensive ignition refresh.

Cons:
– Might be overkill for completely stock setups.

Best for: Tuned or highly modified 2011+ STIs that demand maximum spark reliability.

Expert Opinion: Mishimoto products are consistently reliable in the performance Subaru community. This set is essential for maximizing power output and preventing misfires when running aggressive maps.

Mishimoto Ignition Coil Compatible With Subaru WRX/STi 2.5L 2011+

This is the single-unit version of the high-performance Mishimoto coil designed for the 2011+ 2.5L STi. It carries the same robust engineering and quality testing as the full set but allows for individual coil replacement. If you have confirmed that only one of your existing coils is failing, this is the best ignition coil for subaru sti drivers who want to maintain the Mishimoto performance standard without buying a full set.

Key features that stand out:
– Available as a single unit for targeted replacement.
– High-quality construction ensures longevity and strong spark.
– Direct fit into the 2011+ WRX/STi 2.5L engine bay.

Pros:
– Maintains performance benefits while saving money on a full set.
– Excellent quality control ensures reliability.
– Supports both stock and modified vehicles.

Cons:
– If other coils fail soon after, you will have to purchase again.

Best for: Replacing a single failed Mishimoto or OEM coil on 2011+ STIs while maintaining performance standards.

Expert Opinion: While buying coils individually is often risky, this Mishimoto single unit is engineered to the same high tolerances as the set, making it a reliable drop-in replacement.

Subaru Ignition Coils Forester XT Wrx Sti Legacy Gt Outback XT Baja Turbo – 22433AA542 Set of 4 – Genuine OEM

This set is another genuine OEM offering, specifically highlighting its compatibility across various Subaru turbo EJ platforms (EJ255/EJ257), including the earlier 2004–2010 STI. Genuine OEM coils are always the benchmark for fit and finish. If you prioritize guaranteed compliance and don’t want to worry about potential tuning conflicts that sometimes occur with aggressive aftermarket coils, the 22433AA542 set is the safest bet for maintaining your vehicle’s factory operation.

Key features that stand out:
– Genuine OEM parts for your Subaru EJ255 EJ257 TURBO.
– Guaranteed perfect fitment for 2004-2010 Impreza WRX STI.
– Reliable replacement for stock ignition systems.

Pros:
– Unmatched fitment and quality control from Subaru.
– The standard for long-term daily driver reliability.
– Highly recommended by tuners for non-extreme builds.

Cons:
– Performance enhancement over stock is minimal.

Best for: Owners of older EJ STIs looking strictly for factory replacement parts.

Expert Opinion: When dealing with performance vehicles, choosing a genuine part for sensitive systems like ignition is always a smart decision to avoid frustrating compatibility issues.

PHILTOP Set of 4 Ignition Coil Pack and Iridium Spark Plugs Fits for Subaru 2010-2012 Legacy,2011-2013 Forester,2011-2014 Impreza,2015-2018 WRX STI

The PHILTOP kit offers tremendous value by combining a set of four ignition coils with Iridium spark plugs—the two components that typically need replacement together. This bundle approach simplifies maintenance and ensures you’re installing fresh, compatible parts simultaneously. The coils boast fast ignition times (0.1-0.2 seconds) and high-temperature resistance, while the included Iridium plugs offer exceptional durability and enhanced performance, making this kit an economical way to fully refresh your ignition system.

Key features that stand out:
– Comprehensive kit includes 4 coils and Iridium Spark Plugs.
– Fast Ignition Within 0.1-0.2 Seconds.
– Iridium spark plugs feature a premium central electrode for enhanced durability.

Pros:
– Excellent value for a complete ignition overhaul kit.
– Coils have enhanced features like high voltage output and RF interference protection.
– Simplified purchasing process by bundling necessary components.

Cons:
– Quality of the combined pack may not match dedicated premium single brands.

Best for: Owners performing comprehensive ignition maintenance on their 2015–2018 STI who need both coils and plugs simultaneously.

Expert Opinion: Refreshing both coils and plugs at once is highly recommended for optimal performance. This PHILTOP kit makes the task efficient and affordable while providing modern Iridium technology.

SYKRSS 4-Pack UF665 Ignition Coils Compatible with Subaru WRX STI 13-20, WRX 12-14, Impreza 11-14, Forester 11-13, Legacy 10-12, 2.5L H4 – Replaces for 22433AA600, 22433AA601, 22433AA611

The SYKRSS 4-Pack stands out for its meticulous use of premium materials aimed at long-term durability. These coils are precision-engineered with silicon steel cores, German enameled copper wiring, and Japanese epoxy resin. This focus on material quality ensures heat and voltage resistance, effectively preventing cracking, shorts, and premature failure. They are rigorously tested to eliminate common issues like misfires, rough idling, and check engine lights, making them a trustworthy alternative for the 2013–2020 STI platform.

Key features that stand out:
– Precision-engineered with silicon steel cores, German copper wiring, and Japanese epoxy resin.
– Rigorous Quality Assurance testing eliminates misfires and rough idling.
– Designed to meet or exceed OEM specifications for form, fit, and performance.

Pros:
– Premium material selection leads to high heat and voltage resistance.
– Wide compatibility with later model STI and WRX platforms.
– Focus on voltage stability across various RPM ranges.

Cons:
– Initial startup quality may be slightly inconsistent compared to OEM.

Best for: STI owners (2013–2020) needing a reliable replacement set built with upgraded, durable internal components.

Expert Opinion: The specification of high-quality internal components (like German copper wiring) suggests that SYKRSS is focused on producing a durable product that will last longer than typical budget replacements.

Comparison Insights: Finding Your Best Ignition Coil For Subaru STI

When deciding on the best ignition coil for subaru sti, the choice usually boils down to the car’s model year and your modification level.

For EJ Owners (2004-2010):
If you have the classic EJ-powered STI, the choice is usually between Subaru Genuine OEM (22433AA542) for guaranteed reliability, or the Mishimoto 4-Pack (04-10) for improved performance capacity. If you prioritize OE fidelity, stick with the Genuine set; if you plan on light tuning, the Mishimoto coils offer a noticeable spark improvement.

For Newer STI Owners (2011+):
The later generation STIs have broader options. The Mishimoto Set (2011+) is the performance leader, providing strong output for tuned engines. For the best value replacement set, the TRQ Ignition Coil Set and the SYKRSS 4-Pack offer direct-fit installation and robust internal materials at a competitive price.

The All-In-One Value:
The PHILTOP Set is the standout for total ignition refreshment because it includes high-quality Iridium spark plugs alongside the coils. This is highly recommended if you haven’t replaced your spark plugs in 30,000+ miles.

Singular vs. Full Set:
While the DrCax and Mishimoto single units are available, most experts recommend replacing all four coils simultaneously. If one coil has failed, the others are likely close behind, especially if your STI is aging or subjected to high heat cycles.

Final Verdict: Our Top Picks for the STI

Choosing the correct coil means matching quality and output to your engine’s needs. Here are our specific recommendations:

The Performance Choice (Tuned & Track Use):
The Mishimoto Ignition Coil Compatible With Subaru WRX/STi 2.5L 2011+, Set of 4 takes the top spot for performance drivers. Mishimoto’s engineering focuses on consistent spark energy under high heat and boost, crucial for highly tuned STIs where misfires can lead to serious issues.

The Genuine Reliability Standard:
For owners of any year STI who value OEM performance above all else, the Subaru Genuine Ignition Coils (specifically part 22433AA542 for older models) are the non-negotiable standard. They ensure perfect ECU compatibility and proven long-term dependability.

The Smart Budget Overhaul:
If your STI is misfiring and you need a complete ignition refresh on a budget, the PHILTOP Set of 4 Ignition Coil Pack and Iridium Spark Plugs provides the best bang for your buck. Getting four coils and four premium spark plugs in one affordable package is hard to beat.

Best Ignition Coil For Subaru STI FAQ

What are the main symptoms of a failing ignition coil on an STI?

The most common symptoms include engine misfires (often felt as hesitation or jerking, especially under acceleration), rough or unstable idling, decreased fuel economy, and a decrease in power. You will likely see a check engine light illuminated with P030X codes (P0301, P0302, etc.) indicating a specific cylinder misfire. Replacing the best ignition coil for subaru sti that is failing is essential to prevent damage.

Should I replace just the failing ignition coil, or the whole set?

While you technically can replace only the failing unit (like using the single-pack DrCax or Mishimoto options), it is highly recommended to replace the entire set of four. Ignition coils wear out over similar mileage and heat cycles. If one has failed, the others are likely nearing the end of their lifespan, and replacing all four ensures consistency and prevents recurring misfire issues shortly after the repair.

Does upgrading my ignition coils increase horsepower on my Subaru STI?

Simply replacing your ignition coils won’t significantly increase peak horsepower on a stock engine. However, installing a quality, high-output coil—like the Mishimoto performance options—ensures that the engine receives a consistent, strong spark, particularly under high-boost or high-RPM conditions. This prevents “spark blowout” and misfires, allowing the engine to utilize all the horsepower it’s already tuned for, making the engine feel stronger and more responsive.

Are OEM coils sufficient for a stage 2 modified STI?

For a moderately modified (Stage 2) STI running standard boost levels, high-quality Genuine OEM coils (such as the Subaru 22433AA542) are usually sufficient if they are paired with properly gapped spark plugs. However, if you are planning custom tuning, running aggressive boost maps, or tracking the car frequently, upgrading to an enhanced best ignition coil for subaru sti, like the Mishimoto sets, offers greater margin for error and improved consistency.

How often should ignition coils be replaced on a Subaru STI?

Ignition coil lifespan can vary significantly based on driving conditions, engine heat, and boost levels. On a stock STI, coils often last between 80,000 to 100,000 miles. On tuned or performance vehicles, they may need replacement sooner, typically when you replace your spark plugs, to maintain optimal ignition performance.

Is the installation of a new ignition coil for subaru sti a difficult DIY job?

Replacing ignition coils on a Subaru STI can be slightly more challenging than on vehicles with easier engine access due to the horizontally opposed (boxer) engine layout. Coils are located deep in the engine bay and require careful manipulation, especially on the driver’s side. However, with the right tools (long extensions and swivel joints), the installation of a direct-fit best ignition coil for subaru sti is manageable for a skilled DIY mechanic.