Ignition Coil & Iridium Spark Plugs for Cadillac CTS STS XTS (2008-2019) 3.0L 3.6L V6

Direct-Fit Ignition Coil & Iridium Spark Plugs for 2008-2019 Cadillac CTS, STS, XTS (LLT / LFX V6)

Restores factory ignition efficiency by replacing degraded OEM coils and fouled spark plugs to eliminate misfires and stabilize idle.

The Stock GM High Feature V6 Ignition Weakness

Factory ignition coils on the GM High Feature V6 (LLT and LFX) are notorious for premature thermal degradation. The tightly packaged engine bays of these Cadillac chassis expose the coil packs to extreme operating temperatures. Over time, this constant heat cycling deteriorates the internal epoxy and primary windings, leading to high electrical resistance and voltage leakage. Concurrently, factory spark plugs succumb to electrode wear, expanding the spark gap. This combination inevitably manifests as random cylinder misfires (P0300 codes), severe hesitation under heavy load, and rough idling, and diminished fuel economy. Neglecting these symptoms puts excessive strain on the powertrain control module and catalysts.

The Engineering Solution

This comprehensive replacement kit integrates six precision-wound ignition coils with six advanced iridium-tipped spark plugs. The upgraded coils feature robust internal copper windings coated in high-temperature epoxy to effectively mitigate heat soak and resist electrical breakdown. Their molded silicone boots provide a superior dielectric seal against moisture and oil intrusion, which is critical for maintaining spark integrity in aging V6 engines. Paired with iridium spark plugs—which boast an ultra-fine center electrode—this system requires less firing voltage while delivering a more concentrated, consistent spark kernel. The high melting point of iridium ensures gap stability, providing complete combustion, restored throttle response, and a smooth idle sequence.

Technical Specifications

Compatibility

• 2008-2019 Cadillac CTS (2010-2014 3.0L V6, 2008-2015 3.6L LLT/LFX V6 & 2014-2019 3.6L LF3 V6)
• 2008-2011 Cadillac STS (3.6L V6)
• 2013-2019 Cadillac XTS (3.6L V6)

The Cadillac Precision Standard

Engineered to meet the exacting standards of luxury performance vehicles, ensuring smooth power delivery, optimal fuel atomization, and zero check engine lights (CEL) for your GM High Feature V6.

Common Questions

What is included in this ignition kit?
This complete kit includes 6 precision-wound direct-fit ignition coils with molded silicone boots and 6 iridium-tipped spark plugs to service all 6 cylinders.

Will this kit fit my 2013-2019 Cadillac XTS 3.6L V6?
Yes, this ignition coil and iridium spark plug set is a direct replacement for 2013-2019 Cadillac XTS models equipped with the 3.6L V6 (LFX and LF3).

Which 2008-2019 Cadillac CTS V6 engines does this kit fit?
This UF569-spec kit is made for the 2010-2014 CTS 3.0L (LF1/LFW), 2008-2015 CTS 3.6L (LLT/LFX), and 2014-2019 CTS 3.6L Twin-Turbo (LF3 Vsport). Note that 2016-2019 naturally aspirated CTS 3.6L models use the LGX engine, which takes UF830 coils.

What OEM and aftermarket part numbers do these coils replace?
These coils directly replace part numbers 12590990, 3340078J00, UF569, CLS1226, V40-70-0092, 921-2109, 673-7300, and IC649.

Are modifications required for installation?
Installation is plug-and-play. Both the ignition coils and iridium spark plugs are direct-fit replacements designed to mount directly in the factory locations.