OEM UF620 Ignition Coils & 4504 Double Iridium Spark Plug Set

In this review of the OEM UF620 ignition coil and 4504 double iridium spark plug set, the bottom line is simple: this kit is aimed at owners of specific compact GM models who need a dependable replacement that restores ignition performance and improves starting and fuel economy. The reviewer found the parts engineered to match OE specifications, with iridium plugs promising longer life and coils built with high temperature epoxy and precision winding to reduce misfires and rough idle.

Key Features

• Vehicle Fitment: The set fits 2013-2017 Sonic 1.8L, 2013-2015 Cruze 1.8L and 2010 G3, so buyers can expect direct compatibility with those engines.
• Iridium Spark Plug: The double iridium central electrode is designed to extend spark plug life and support more stable idle speed compared with standard plugs.
• Improved Ignition Response: The coils are engineered to improve ignition timing and reduce crank time, helping faster starts and fewer misfires.
• Durable Construction: Epoxy resin filling rated to 140 C and high quality enameled copper winding aim to resist corrosion and maintain insulation under heat.
• OE-Level Fit: KAX matched or improved OE design for components so installation is straightforward and intended to function like the original parts.
• Complete Replacement Kit: The package includes 1 UF620 ignition coil and 4 4504 spark plugs, making it a one-stop repair for the ignition side of the engine.

Who It's For

This kit is best for DIY mechanics and independent shops servicing the listed GM compacts who want an all-in-one ignition replacement that mirrors OE design. It suits drivers experiencing hard starts, long crank times, misfires, inconsistent shifts related to ignition issues, or declining fuel economy who want to address ignition coils and spark plugs together.

It is not aimed at vehicles outside the stated fitment or owners seeking performance tuning parts for higher output; those customers should look for performance-specific coils or custom plug gaps. Also, if a vehicle has unrelated electrical faults, this kit will not resolve wiring or ECU problems.

Pros & Cons

Pros

• Direct-fit design for the listed models reduces installation time and fitment uncertainty.
• Iridium plugs offer longer life and help stabilize idle and starting performance.
• Coils built with high temperature epoxy and precise winding aim to improve reliability under heat.

Cons

• Fitment is limited to specific 1.8L models, so it is not a universal replacement.
• The kit addresses ignition components only and will not fix non-ignition engine issues.

Specifications

Our Verdict

This UF620 ignition coil and 4504 double iridium spark plug set is a practical, value-oriented replacement for owners of the listed GM 1.8L models. It pairs longer-lasting iridium plugs with coils built to OE-like standards, making it a sensible choice to restore starting reliability, reduce misfires and improve fuel economy without unnecessary extras.

Frequently Asked Questions

Will this kit fit my Cruze or Sonic?
The set is specified for 2013-2017 Sonic 1.8L, 2013-2015 Cruze 1.8L and 2010 G3; confirm engine size and year before purchasing.

Do the iridium plugs need a different gap?
Iridium plugs are designed to perform with OE gaps; follow the vehicle manual or the plug manufacturer guidance for any gap checks.

Will replacing these parts fix engine misfires?
If misfires are caused by worn coils or fouled spark plugs, this kit should correct them, but it will not resolve misfires from fuel or sensor issues.