The 2005 GS300 3GR-FSE is a capable V6 platform that benefits from proper standalone engine management.
The 2005 Lexus GS300 3GR-FSE platform has a strong tuning community, and standalone ECU support opens what the factory management keeps locked down. The Tuned By Shawn Boomslang PNP Wiring Harness for the Haltech Nexus connects directly to your factory harness without any permanent modifications, giving the Haltech Nexus full standalone engine control. No cutting, no splicing, fully reversible.
Advantages
- Throttle response that's precise and proportional
- Fuel and ignition timing calibrated to your actual modifications, not Toyota's conservative baseline
- Idle stability that's locked in regardless of temperature
- Consistent engine behavior across temperature ranges
- A proper tuning foundation for this specific chassis
Features
- Plug-and-play fitment for 2005 Lexus GS300 3GR-FSE, all transmission types
- Compatible with Haltech Nexus R3, R5, S2, and S3 ECUs
- No cutting or splicing of factory wiring
- OEM-quality connectors, USA-built by Boomslang Fabrication
- Fully reversible, factory harness preserved
- For competition and off-road use
The Details
Built specifically for this vehicle's connector layout with OEM-spec connectors and correct wire gauge throughout. Your factory harness stays completely untouched and the vehicle can return to stock at any time. In automatic transmission applications, the factory ECU remains in parallel for transmission control while the Haltech Nexus manages the engine.
Kit Includes
- 1x Boomslang PNP wiring harness for 2005 Lexus GS300 3GR-FSE
- Haltech Nexus ECU sold separately
Fitment
2005 Lexus GS300 3GR-FSE, All Transmission Types.