Ignition Coil & Iridium Spark Plugs for Subaru Forester (2017-2018) 2.5L

Direct-Fit Ignition Coil & Iridium Spark Plugs for 2017-2018 Subaru Forester

Restores lost power, resolves misfire codes, and ensures complete combustion for the FB25 naturally aspirated boxer engine.

The Stock Forester Ignition Breakdown

Over time, the factory coil packs on the SJ chassis Forester are subjected to extreme thermal cycling and intense radiant heat directly from the horizontally opposed cylinder banks. This continuous thermal stress degrades the internal epoxy resin and primary winding insulation, leading to voltage leaks. When paired with worn conventional or degraded OEM spark plugs, the resulting increased resistance forces the coils to work harder, accelerating failure. Symptoms typically manifest as hesitation under load, erratic idle, reduced fuel efficiency, and eventually P0300-series misfire diagnostic trouble codes (DTCs), which can severely compromise catalytic converter health if left unaddressed.

The Engineering Solution

This comprehensive ignition service kit bundles high-output ignition coils with premium Iridium-tipped spark plugs to permanently resolve weak spark issues. The coils feature upgraded copper wire in both the primary and secondary windings, encased in a high-dielectric epoxy that resists heat soak and vibration inherent to the boxer architecture. The included Iridium spark plugs utilize an ultra-fine center electrode and a tapered ground electrode, drastically lowering the voltage requirement to bridge the plug gap. This specialized metallurgy resists spark erosion and fouling, guaranteeing a concentrated, consistent spark front. The result is optimized flame propagation, restored factory horsepower output, smoothed idle characteristics, and long-term electrical reliability that meets or exceeds stringent OE specifications.

Technical Specifications

Compatibility

• 2017 Subaru Forester 2.5L
• 2018 Subaru Forester 2.5L

The Subaru Dependability Standard

Engineered for the rigorous demands of the symmetrical all-wheel-drive platform, this ignition overhaul ensures your Forester maintains its legendary reliability on the trail or the daily commute, delivering consistent spark without the dreaded flashing check engine light.