Ignition Coil and Iridium Spark Plugs for Chevrolet Trailblazer (2006-2009) 4.2L

Direct-Fit Ignition Coil and Iridium Spark Plug Service Kit for 2006-2009 Chevrolet Trailblazer

What it Does: Replaces degraded factory coil packs and worn spark plugs with high-dielectric coil-on-plug assemblies and fine-wire iridium plugs to restore precise secondary ignition voltage and clean combustion.

The Stock Trailblazer Secondary Voltage Breakdown

The Atlas LL8 inline-six engine relies on individual coil-on-plug assemblies mounted in deep cylinder head wells. Over extended thermal cycles, the factory epoxy encapsulation develops microscopic dielectric breakdown, and the primary-to-secondary copper windings suffer thermal fatigue. This degradation leads to intermittent primary current resistance, high-RPM misfires (DTC P0300-P0306), unburnt hydrocarbon accumulation in the catalytic converter, and rough idle stabilization under load.

The Engineering Solution

This 6-cylinder refresh kit features reinforced ignition coils engineered with high-conductivity internal copper windings and high-grade thermal resin encapsulation to resist dielectric breakdown under extreme underhood heat soak. Paired with fine-wire iridium spark plugs, the assembly lowers required secondary voltage, ensures stable spark kernel propagation, and maintains exact electrode gap tolerances over severe duty cycles. Blade-style direct-fit terminals guarantee minimal contact resistance and zero-modification installation.

Technical Specifications

Compatibility

• 2006-2009 Chevrolet Trailblazer LS 4.2L L6
• 2006-2009 Chevrolet Trailblazer LT 4.2L L6

The Chevrolet Heavy-Duty Standard

Engineered to handle the constant thermal loads of heavy towing, stop-and-go utility, and off-pavement hauling without coil breakdown or spark blowout across the entire rev range.