KacuYelin Ignition Coil Pack & Iridium Spark Plug Kit for Ford 2.0L/2.5L (Set of 4) — OEM-fit, Long-Life

The KacuYelin UF621 kit is a direct-replacement set of four ignition coils and four iridium spark plugs engineered to restore reliable ignition for 2.0L and 2.5L Ford-family 4-cylinder engines.

This complete ignition kit is built to match OEM fit and wiring for many Ford, Lincoln, Mercury and Mazda 2.0L/2.5L naturally aspirated models from 2009–2022. The coils are wound with high-purity copper, encased in heat-resistant epoxy and a silicon-steel core for steady high-voltage output, while the iridium plugs use continuous-laser-welded center electrodes and high-alumina ceramics for long service life and stable spark performance. The set replaces OE references such as UF621, C1658 and GN10507 and is intended as a plug-and-play repair to reduce misfires and improve responsiveness when installed correctly.

How will swapping to these coils and iridium plugs affect drivability?

Replacing worn coils and plugs can restore consistent ignition timing and combustion quality, which often reduces hesitation, rough idle and hard starting. While results vary by vehicle condition, owners typically notice smoother throttle response and fewer misfire codes after installing fresh ignition parts.

• Direct-fit replacement for OEM mounting and wiring—no modifications required
• High-purity copper windings promote steady voltage delivery to spark plugs
• Iridium center electrodes sustain a strong, focused spark for cleaner combustion
• May reduce engine stumbling and restore normal idle and acceleration

Are these parts compatible with my vehicle model and year?

The kit covers many naturally aspirated 2.0L and 2.5L Ford-family models; confirm fitment by matching year, brand, submodel and engine in the vehicle fit tool before ordering. It does not fit turbocharged (Turbo/T) engines—check your engine code or factory sticker if unsure.

• Fits Ford Escape (2009–2019 2.5L), Fusion (2010–2020 2.5L; 2013–2020 2.0L), C‑Max (2013–2018 2.0L)
• Also fits Transit Connect (2014–2022 2.5L), Police Responder and SSV hybrids (2019–2020 2.0L variants)
• Compatible with Mercury Mariner (2009–2011), Milan (2010–2011) and Lincoln MKZ (2011–2012 2.5L; 2013–2020 2.0L)
• Mazda Tribute 2009–2010 2.5L covered; confirm by cross-referencing OE numbers

What materials and manufacturing details matter for longevity?

KacuYelin coils use German-imported copper winding and a silicon-steel core with high-temperature epoxy to resist heat and oxidation. The iridium plugs employ a continuous 360° laser-welded electrode and 95% high‑alumina ceramic insulator, designed for higher wear resistance and improved insulation compared with conventional plugs.

• Coil construction: high-purity copper windings + silicon steel core + heat-resistant epoxy
• Plug construction: iridium-tipped electrode with continuous laser welding for stronger sparks
• High‑alumina ceramic insulator improves thermal stability and electrical isolation
• Manufactured in TS16949-certified facilities with OEM-equivalent dimensions

How should I install and maintain this ignition kit?

Installation is intended to be bolt‑in: remove old coils and plugs, inspect wells and connectors, torque new plugs to spec, and install coils snugly. Regular inspection of ignition boots and wiring and following manufacturer torque and gap recommendations will extend service life.

• Use correct spark plug gap and torque values for your engine—consult service manual
• Inspect ignition boots and electrical connectors for corrosion before installation
• Replace coils and plugs as a matched set when encountering misfires or rough running
• Note: do not use on turbocharged engines; verify engine aspiration first

Who is this for: The KacuYelin UF621 coil and iridium spark plug kit is intended for DIY mechanics and professional technicians repairing naturally aspirated 2.0L and 2.5L Ford-family vehicles that need a reliable, OEM-dimension replacement. It’s suited to owners experiencing misfires, poor idle, hard starts or diminished responsiveness who want a long-service iridium plug option combined with high-quality coils from a TS16949-certified manufacturer.