Ignition Coil + Iridium Spark Plugs for Subaru Impreza (2008-2010) 2.5L

Direct-Fit Ignition Coil and Iridium Spark Plug Kit for 2008-2010 Subaru Impreza

What it Does: The direct-fit ignition coil and iridium spark plug kit restores primary and secondary ignition efficiency on the 2008-2010 Subaru Impreza to eliminate cylinder misfires, stabilize idle oscillation, and restore lost combustion pressure.

The Stock Subaru Impreza Thermal Degradation and Secondary Leakage

Due to the horizontally opposed cylinder configuration of the Subaru boxer engine, factory ignition coils sit in tight proximity to the cylinder heads and exhaust manifolds. Over thousands of miles, intense heat soak degrades the internal epoxy potting and hardens the silicone spark plug boots. This leads to dielectric breakdown, micro-arcing, and intermittent P0301-P0304 fault codes. Furthermore, factory plug electrodes widen over time, dramatically raising the required discharge voltage and placing excessive electrical load on aging OEM UF508 and 22433AA541 ignition coils.

The Engineering Solution

This comprehensive ignition service kit restores factory ignition integrity using high-dielectric epoxy resin casings and thermal-resistant magnetic copper secondary windings that resist high-voltage tracking under heavy acceleration. Paired with laser-welded fine-wire iridium spark plugs, the 0.6mm iridium center electrode significantly reduces quenching while requiring less discharge voltage from the coils. High-grade fluorosilicone spark plug boots protect against ambient engine oil intrusion and horizontal tube heat, guaranteeing consistent flame propagation and crisp throttle response across the entire RPM band.

Technical Specifications

Compatibility

• 2008-2010 Subaru Impreza 2.5i Sedan 2.5L H4 (EJ253)
• 2008-2010 Subaru Impreza 2.5i Hatchback 2.5L H4 (EJ253)
• 2008-2010 Subaru Impreza Outback Sport 2.5L H4 (EJ253)

Frequently Asked Questions

Does this fit the GE/GH Impreza?
Yes, this is a direct fit for the 2008-2010 Subaru Impreza equipped with the naturally aspirated EJ253 2.5L engine.

Are these spark plugs pre-gapped for installation?
Yes, the iridium plugs come pre-gapped to factory clearance; verify gently with a feeler gauge and torque directly into the cylinder heads to 15-20 lb-ft.

The Subaru Boxer Standard

Because accessing ignition components within the compact chassis clearance of the GE/GH boxer platform requires dedicated labor, installing matched high-temp coils and iridium plugs together eliminates repetitive maintenance and delivers the long-term ignition power your Subaru demands.