The Impreza RS sits right at the start of what makes a Subaru a great build platform, and standalone ECU management is how you explore that properly.
The Subaru Impreza RS EJ25 runs a boxer engine with genuine tuning potential, and the factory ECU is the limiting factor in reaching it. 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 delivery that's precise and repeatable instead of factory ECU conservative
- Throttle response that's direct and proportional to your inputs
- Flat-four character that comes through clearly when the tune is built for the actual engine
- Fueling that stays accurate at temperature, not chasing a moving target
- A tune that reflects your modifications instead of compensating for them
Features
- Plug-and-play fitment for 1999-2002 Subaru Impreza RS EJ25, 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 1999-2002 Subaru Impreza RS EJ25
- Haltech Nexus ECU sold separately
Fitment
1999-2002 Subaru Impreza RS, Manual Transmission.