Nexus S3 ECU & 1JZ-GTE Plug 'n' Play Adapter Harness

The Haltech Nexus S3 ECU & Toyota Supra 1JZ-GTE 1989-1992 Plug 'n' Play Adapter Harness Kit offers a solution for enhanced engine management in your 1989-1992 Toyota Supra 1JZ-GTE manual transmission vehicle. This kit bypasses the limitations of the factory ECU, enabling precise control over boost, timing, and power delivery that is tailored to your specific modifications. The system features a plug-and-play design, meaning no cutting or splicing of the factory wiring is required, and the installation is fully reversible. The harness is constructed with OEM-quality connectors and is USA-built by Boomslang Fabrication, ensuring durability and reliability. This kit is compatible with Haltech Nexus R3, R5, S2, and S3 ECUs and is intended for competition and off-road use. The kit includes the Boomslang PNP wiring harness, the Haltech Nexus S3 ECU, and an Air Temp Sensor with a small thread (M14 x 1.5). It provides a clean, vehicle-specific foundation for tuners to build a proper engine map, leading to more predictable power delivery and confidence that dyno results will translate to track performance.