The STI responds to boost and tuning the factory ECU was never built to deliver.
The Subaru STI is a capable platform, but factory engine management puts a ceiling on what's possible. The Tuned By Shawn PNP Wiring Harness Kit 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
- Boost that builds and holds exactly where you dial it in, not where the factory knock strategy allows
- Timing that advances where it should instead of pulling at the first sign of heat
- Power delivery that's linear and predictable through the entire boost curve
- A tune built around your exact modifications, not averaged factory parameters
- Confidence that what happened on the dyno is what happens on the track
Features
- Plug-and-play fitment for 2005-2006 Subaru STI, manual transmission
- 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 car can return to stock at any time. The Haltech Nexus takes full engine control once installed, giving your tuner a clean vehicle-specific foundation to build a proper map from.
Kit Includes
- 1x Boomslang PNP wiring harness for 2005-2006 Subaru STI
- Haltech Nexus ECU sold separately
Fitment
2005-2006 Subaru STI, Manual Transmission.