Ignition Coil and Iridium Spark Plugs for Infiniti Q45 (1997-2001) 4.1L

Direct-Fit Ignition Coil and Iridium Spark Plug Kit for 1997-2001 Infiniti Q45

What it Does: The ignition coil and iridium spark plug kit replaces aged factory coil packs and degraded plugs on the 1997-2001 Infiniti Q45 to restore peak spark energy, stabilize idle, and eliminate cylinder misfires.

The Stock Infiniti Q45 Thermal Degradation Weakness

The factory ignition setup on the FY33 chassis suffers from severe thermal fatigue due to tightly packed engine bay packaging and prolonged heat-soak around the cylinder heads. Over time, the internal primary and secondary copper windings inside the OEM coil packs break down, causing high-voltage dielectric breakdown and intermittent spark blowout under load. Concurrently, factory standard-metal spark plugs erode at the ground electrode, expanding the plug gap and forcing degraded coils to draw excessive primary current, which ultimately triggers downstream ignition misfires and unburnt hydrocarbon catalyst contamination.

The Engineering Solution

This comprehensive service kit replaces all eight positions with high-dielectric epoxy-molded pencil ignition coils and fine-wire iridium spark plugs matched for the VH41DE architecture. Each coil housing features reinforced thermoplastic PBT construction to resist thermal cycling, along with internal magnetic core laminations wound to match factory dwell times while delivering consistent secondary output above 30kV. Paired with laser-welded 0.6mm iridium center-electrode spark plugs, this kit provides superior spark kernel propagation, lower required firing voltages, and exceptional resistance to carbon fouling under cold-start conditions.

Technical Specifications

Compatibility

• 1997 Infiniti Q45 Base / Touring 4.1L V8
• 1998 Infiniti Q45 Base / Touring 4.1L V8
• 1999 Infiniti Q45 Base / Touring 4.1L V8
• 2000 Infiniti Q45 Base / Touring / Anniversary Edition 4.1L V8
• 2001 Infiniti Q45 Base / Touring 4.1L V8

Frequently Asked Questions

Does this fit the FY33 Q45?
Yes, this is a direct fit for the 1997-2001 Infiniti Q45 equipped with the VH41DE engine.

Are these spark plugs pre-gapped for the VH41DE?
Yes, the iridium plugs arrive pre-gapped to factory specifications, though verifying clearance before installation is always recommended.

The Infiniti VIP Caliber

Designed to maintain the legendary smoothness and linear power delivery of classic JDM luxury platforms, this ignition assembly restores crisp throttle response and clean combustion without altering factory ECU calibrations.