Ignition Coil + Spark Plugs for Subaru Baja (2004-2006) 2.5L

Direct-Replacement Ignition Coil and Denso Iridium Spark Plug Kit for 2004-2006 Subaru Baja (BT)

What it Does: The direct-fit ignition kit restores combustion efficiency and eliminates cylinder misfires under boost on the 2004-2006 Subaru Baja Turbo.

The Stock Subaru Baja Ignition Coil Breakdown

Factory coil packs on the turbocharged EJ255 suffer from severe thermal degradation due to their horizontal positioning tight against the cylinder heads and exhaust manifolds. Over time, engine bay heat cycles break down the primary and secondary internal copper windings, micro-crack the epoxy potting material, and harden the dielectric silicone boots. This deterioration causes high-voltage secondary arc-through, unmetered energy loss, and spark blow-out under peak manifold boost pressure, manifesting as erratic idle, hesitation, and generic P0300 or cylinder-specific misfire codes.

The Engineering Solution

This service kit replaces fatigued factory units with high-dielectric reinforced UF508-spec coil-on-plug modules paired with Denso Iridium spark plugs. The replacement coils utilize dense magnetic core windings insulated with premium epoxy potting to resist thermal shock and electrical breakdown. Paired with Denso's fine-wire 0.4mm iridium center electrode and ground strap, this setup substantially lowers the required ionization voltage, stabilizing the flame kernel across the combustion chamber. The thermal properties of the iridium alloy resist erosion under continuous boost, ensuring stable ignition timing and restoring OEM drivability.

What's Included

• 4 Ignition Coils (Replacement for UF508)
• 4 Denso Iridium Spark Plugs

Technical Specifications

Compatibility

• 2004 Subaru Baja Turbo 2.5L H4
• 2005 Subaru Baja Turbo 2.5L H4
• 2006 Subaru Baja Turbo 2.5L H4

Frequently Asked Questions & Fitment Warnings

Does this fit the BT Baja?

Yes, this is a direct fit for the 2004-2006 Subaru Baja equipped with the EJ255 2.5L Turbo engine. This kit does not fit naturally aspirated EJ253 non-turbo engines or models utilizing external spark plug wires.

Are plug wires included and what are the torque requirements?

Spark plug wires are not included because this application utilizes direct coil-on-plug technology; plugs must be torqued to factory specifications (15-18 lb-ft) without over-tightening coil mounting bolts.

The Subaru Performance Caliber

Engineered for the demands of the horizontally opposed boxer turbo platform, this ignition service kit maintains accurate timing and sharp throttle response across all RPM bands.