Ignition Spark Plugs and Wires for Lexus GS400 (1998-2000) 4.0L

Direct-Fit Ignition Coils and Iridium Spark Plugs for 1998-2000 Lexus GS400

Restores lost ignition efficiency to correct misfires and hesitation in the 1UZ-FE engine. This complete bundle replaces aging OEM ignition coils and worn spark plugs with a direct-replacement Aero ignition coil kit and NGK iridium spark plugs to stabilize engine performance.

The Stock GS Ignition Weakness

Over decades of heat cycling, the original 1UZ-FE ignition coils and plug wires suffer from dielectric breakdown. The internal epoxy potting degrades, leading to micro-arcing and voltage leaks that bypass the spark plug entirely. This translates to unburned fuel, sluggish throttle response, random cylinder misfires under load, and a blinking check engine light. Furthermore, factory copper or platinum plugs experience electrode erosion over time, increasing the spark gap and placing additional strain on the already compromised ignition coils, accelerating their failure.

The Engineering Solution

This complete ignition overhaul kit addresses the inherent electrical wear of the S160 chassis. The upgraded Aero ignition coils utilize high-density copper internal windings and specialized high-temperature epoxy to resist thermal breakdown, maintaining consistent voltage output even under extreme under-hood temperatures. Paired with NGK Iridium spark plugs, the system benefits from a micro-welded iridium center electrode that requires less voltage to bridge the gap. This reduces the electrical load on the coils while providing a highly concentrated, powerful spark kernel. The combination ensures complete combustion, restoring the factory 300-horsepower output, stabilizing the idle, and maximizing fuel efficiency without triggering ECM fault codes.

Technical Specifications

Compatibility

• 1998 Lexus GS400 4.0L V8
• 1999 Lexus GS400 4.0L V8
• 2000 Lexus GS400 4.0L V8

The Lexus Reliability Standard

Built to maintain the legendary refinement of the 1UZ-FE, this ignition kit ensures smooth, uninterrupted power delivery and factory-level reliability without triggering dashboard CELs.