Ignition Coil & Iridium Spark Plugs for Subaru Forester (2014-2016) 2.5L H4

Direct-Replacement Ignition Coil & Iridium Spark Plugs for 2014-2016 Subaru Forester (FB25 / SJ)

Restores optimal combustion and eliminates misfire conditions associated with degraded factory ignition systems on the 2.5L FB25 platform.

The Stock Forester Ignition Weakness

The OEM ignition coils and standard plugs on the SJ-chassis Forester are highly susceptible to thermal degradation and dielectric breakdown over extended mileage. Because the FB25 boxer engine positions the spark plugs horizontally against the frame rails, they endure significant radiant heat cycling. Over time, the factory coil packs experience internal winding resistance variations, leading to weak spark energy, erratic idling, partial throttle hesitation, and eventual P0300-series misfire codes. Simultaneously, standard plug electrodes erode, increasing the spark gap, which demands higher firing voltages and prematurely stresses the factory coil packs to the point of failure.

The Engineering Solution

This comprehensive ignition service kit bundles high-output ignition coils with premium iridium-tipped spark plugs to re-establish peak firing efficiency. The upgraded coils feature enhanced copper windings shielded by high-temperature epoxy, preventing voltage leaks and ensuring a consistent spark output even under heavy thermal loads. Paired with the ultra-fine wire iridium center electrodes, these plugs require lower firing voltage while delivering a more concentrated spark kernel. This combination significantly optimizes fuel burn within the cylinder, rectifying hesitation, restoring factory fuel economy, and ensuring reliable cold starts. The iridium construction also provides superior resistance to electrode wear, extending service intervals well beyond OEM copper or platinum variants.

Technical Specifications

Compatibility

• 2014 Subaru Forester 2.5L H4
• 2015 Subaru Forester 2.5L H4
• 2016 Subaru Forester 2.5L H4

The Subaru Standard

Whether navigating technical off-road trails or managing daily commutes, a robust ignition system is critical for the symmetrical AWD powertrain. This kit delivers the reliable power delivery and rugged dependability expected from the Forester platform.

Common Questions

Will this ignition coil and spark plug kit fit my 2014-2016 Subaru Forester 2.5L?
Yes, this kit is a direct replacement for all 2014, 2015, and 2016 Subaru Forester models equipped with the naturally aspirated 2.5L H4 (FB25) engine on the SJ chassis.

Does this kit fit the 2.0XT turbocharged Forester or 2017-2018 models?
This kit is engineered specifically for the 2014-2016 Subaru Forester 2.5L H4 naturally aspirated engine.

What is included in this tune-up package?
The kit bundles direct-replacement high-output ignition coils featuring enhanced copper windings and high-temperature epoxy shielding along with matching ultra-fine wire iridium-tipped spark plugs.

What symptoms does replacing the coils and spark plugs address?
Replacing degraded factory coils and worn plugs resolves weak spark energy, erratic idling, partial throttle hesitation, hard cold starts, and P0300-series misfire codes caused by thermal breakdown on the horizontal boxer cylinder heads.

Are modifications required during installation?
The ignition coils and iridium spark plugs are direct-replacement components built to fit the factory mounting points and connectors on the 2.5L FB25 engine without modification.