Ignition Coil & Iridium Spark Plugs for Lexus SC430 (2002-2010) 4.3L V8

High-Output Ignition Coil & Iridium Spark Plug Kit for 2002-2010 Lexus SC430 (3UZ-FE / UZZ40)

Restores lost power and eliminates misfires by providing a consistent, high-voltage spark for complete combustion in the 3UZ-FE V8.

The Stock SC430 Ignition Degradation

The factory ignition coils on the UZZ40 SC430 are highly susceptible to heat degradation over extended mileage. Mounted directly atop the 3UZ-FE cylinder heads, these units endure continuous thermal cycling that eventually breaks down the internal epoxy potting and primary windings. This thermal degradation leads to voltage leaks, weak spark output, and increased electrical resistance. The mechanical result is hesitation under load, rough idling, and persistent P0300-series misfire codes. Paired with fouled or worn factory plugs, the system struggles to bridge the spark gap efficiently, causing incomplete combustion, diminished fuel economy, and unburned fuel passing to the catalytic converters.

The Engineering Solution

This replacement kit overhauls the aging UZZ40 ignition system with eight high-dielectric epoxy-filled ignition coils designed to permanently resist thermal breakdown. The upgraded coils utilize high-grade copper windings to ensure maximum voltage transfer to the plug, mitigating spark blowout under heavy load. Accompanying the coils are eight performance iridium spark plugs featuring an ultra-fine wire center electrode. This specialized design requires less primary voltage to fire while delivering an intense, concentrated spark. The iridium construction offers superior resistance to electrical wear and oxidation compared to standard OEM platinum plugs, designed to ensure a stable gap and optimal timing over a prolonged service interval.

Technical Specifications

Compatibility

• 2002 Lexus SC430 4.3L V8
• 2003 Lexus SC430 4.3L V8
• 2004 Lexus SC430 4.3L V8
• 2005 Lexus SC430 4.3L V8
• 2006 Lexus SC430 4.3L V8
• 2007 Lexus SC430 4.3L V8
• 2008 Lexus SC430 4.3L V8
• 2009 Lexus SC430 4.3L V8
• 2010 Lexus SC430 4.3L V8

The Lexus Reliability Standard

Since the SC430 represents peak JDM luxury touring, restoring the 3UZ-FE to its factory parameters ensures smooth, linear power delivery and reliable daily drivability without triggering intermittent check engine lights.

Common Questions

Will this ignition coil and spark plug kit fit my 2002-2010 Lexus SC430?
Yes, this kit is a direct replacement for all 2002-2010 Lexus SC430 (UZZ40) models equipped with the 4.3L 3UZ-FE V8 engine.

What is included in the box?
The kit includes 8 high-dielectric epoxy-filled ignition coils with copper windings and 8 ultra-fine wire iridium spark plugs to service all 8 cylinders.

Which factory and aftermarket part numbers does this coil set replace?
These ignition coils cross-reference with part numbers 9091902230, 5C1196, IC336SB, and UF230.

How do the iridium spark plugs compare to the stock plugs?
The included iridium plugs use an ultra-fine wire center electrode that requires less primary voltage to fire while offering higher resistance to electrical wear and oxidation than standard platinum plugs.

Will this kit help resolve misfires and rough idling on my 3UZ-FE?
Yes, replacing heat-degraded factory coils and worn plugs restores consistent high-voltage spark output to eliminate hesitation under load, rough idling, and P0300-series misfire codes.