Ignition Coil + Spark Plugs for Infiniti FX45 (2003-2008) 4.5L

Direct-Fit Ignition Coil and Spark Plug Tune-Up Kit for 2003-2008 Infiniti FX45 4.5L (S50 / VK45DE)

What it Does: The ignition coil and spark plug service kit restores factory combustion efficiency, eliminates cylinder misfires, and stabilizes idle on the 2003-2008 Infiniti FX45.

The Stock Infiniti FX45 Secondary Ignition Breakdown

The VK45DE V8 engine bay in the S50 chassis generates significant thermal loads due to tight engine packaging and dense under-hood heat soak. Over mileage and continuous heat cycles, factory coil pack boots harden, develop microscopic dielectric fissures, and leak primary voltage to the aluminum cylinder head rather than the plug gap. Simultaneously, fine-wire spark plugs experience electrode erosion, widening gap clearance beyond standard factory tolerance. This increased electrical resistance forces aged coils to operate at saturated dwell times, leading to internal primary/secondary winding failure, erratic misfire codes (P0300 through P0308), degraded fuel trim corrections, and sluggish throttle response.

The Engineering Solution

This comprehensive service pack pairs eight direct-fit coil-on-plug units with matched application-specific spark plugs to overhaul the primary ignition circuit. Built with high-dielectric epoxy potting and heat-resistant silicone boots, these coils isolate high-voltage discharge and resist dielectric punch-through under high thermal degradation. Matched high-durability center electrodes resist spark erosion to maintain a stable arc gap across varying cylinder pressures. Swapping plugs and coils concurrently restores precise burn duration, protects catalytic converters from unburned hydrocarbons, and renews crisp throttle tip-in across the powerband.

Technical Specifications

Compatibility

• 2003 Infiniti FX45 Base 4.5L V8 (VK45DE / S50)
• 2004 Infiniti FX45 Base 4.5L V8 (VK45DE / S50)
• 2005 Infiniti FX45 Base 4.5L V8 (VK45DE / S50)
• 2006 Infiniti FX45 Base 4.5L V8 (VK45DE / S50)
• 2007 Infiniti FX45 Base 4.5L V8 (VK45DE / S50)
• 2008 Infiniti FX45 Base 4.5L V8 (VK45DE / S50)

Frequently Asked Questions

Does this fit the S50 FX45?
Yes, this is a direct fit for the 2003-2008 Infiniti FX45 equipped with the VK45DE engine.

Is an ECU reset or tune required after installation?
No ECU tune is needed, though clearing stored DTC misfire codes and resetting fuel trims via OBD-II allows the ECU to adapt quickly to renewed ignition efficiency.

The Infiniti Performance Standard

Preserve the aggressive, high-revving character and signature exhaust note of your performance crossover by keeping the 32-valve V8 firing on all eight cylinders with uncompromising electrical integrity.