{"product_id":"ignition-coil-and-iridium-spark-plugs-for-gmc-envoy-2006-2009-4-2l","title":"Ignition Coil and Iridium Spark Plugs for GMC Envoy (2006-2009) 4.2L","description":"\u003ch2\u003eDirect-Fit Ignition Coil and Iridium Spark Plug Kit for 2006-2009 GMC Envoy\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003ePrimary Function:\u003c\/strong\u003e Restores high-voltage secondary ignition output and precise flame front propagation across all six cylinders on the Atlas 4.2L inline-six engine.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock Envoy LL8 Thermal Breakdown\u003c\/h3\u003e\n\u003cp\u003eThe Vortec 4200 inline-six configuration places the rear coil-on-plug modules directly under severe thermal load near the firewall. Over extended runtimes, factory epoxy insulation degrades, causing internal winding breakdown, dielectric puncture, and intermittent secondary voltage arcing. Coupled with factory platinum plug gap erosion, this degradation triggers P0300-P0306 multi-cylinder misfires, unburnt hydrocarbon build-up in the catalytic converter, and rough idle under load.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis full tune-up assembly integrates high-temperature dielectric thermoplastic housings and premium electrolytic copper primary\/secondary windings to prevent thermal insulation breakdown. The matching fine-wire iridium spark plugs feature a 0.6mm laser-welded electrode with a high-melting-point core, significantly reducing required firing voltage and resisting erosion under high combustion chamber temperatures. Blade terminals and precision-molded boots provide weather-tight, vibration-dampened connectivity directly to the factory harness.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;\"\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e2006-2009 GMC Envoy (4.2L L6)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eEngine \/ Chassis\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eVortec 4200 LL8 \/ GMT360\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eStock Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e291 hp \/ 277 lb-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eUF497, UF-497\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e2006 GMC Envoy (SLE, SLT, Denali 4.2L L6)\u003c\/li\u003e\n  \u003cli\u003e2007 GMC Envoy (SLE, SLT 4.2L L6)\u003c\/li\u003e\n  \u003cli\u003e2008 GMC Envoy (SLE, SLT 4.2L L6)\u003c\/li\u003e\n  \u003cli\u003e2009 GMC Envoy (SLE, SLT 4.2L L6)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eThe GMC Heavy-Duty Standard\u003c\/h3\u003e\n\u003cp\u003eBuilt to handle continuous high-load towing and stop-and-go utility cycles, these components maintain stable dwell-time response and full combustion efficiency without heat-soak dropoff.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50454116499704,"sku":"DS-E328SO0YQ","price":118.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/ignition-coil-and-iridium-spark-plugs-for-gmc-envoy-2006-2009-4-2l-1.jpg?v=1788726536","url":"https:\/\/performancechiptuning.com\/fr\/products\/ignition-coil-and-iridium-spark-plugs-for-gmc-envoy-2006-2009-4-2l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}