Haltech Nexus S2 ECU & Subaru STI 2004 Plug 'n' Play Adapter Harness Kit (HT-651078)
Haltech Nexus S2 ECU & Subaru STI 2004 Plug 'n' Play Adapter Harness Kit (HT-651078)
Boomslang plug and play wiring harness for Haltech Nexus
Haltech air temp sensor HT-010200

Vendor:Tuned By Shawn

Haltech Nexus S2 ECU & Subaru STI 2004 Plug 'n' Play Adapter Harness Kit (HT-651078)

SKU: HT-651078

Nexus Must-Haves
$2,670.00
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From Shawn: Not sure this product is right for your build? Email me at service@tunedbyshawn.com before you order. I answer these myself.
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Manufacturer Limited Warranty

Product details

Description

This Tuned By Shawn plug-and-play kit (HT-651078) pairs the Haltech Nexus S2 ECU with the matching Boomslang adapter harness (BF29112) for the 2004 Subaru STI (GD chassis, EJ257 engine) with a manual transmission. The harness plugs into the factory engine harness where the stock ECU connects, so the Nexus S2 takes over full standalone engine management with no cutting, splicing or repinning.

Vehicle Fitment

  • 2004 Subaru STI (manual transmission)

Boomslang part number: BF29112. Confirm your model year, engine and transmission before ordering. Similar-looking vehicles often use a different factory ECU connector or pinout and need a different harness.

ECU Included

This kit includes the Haltech Nexus S2 ECU, and the Boomslang harness is built for its connectors.

Features

  • Vehicle-specific plug-and-play fitment for the 2004 Subaru STI
  • Plugs into the factory engine harness with no cutting, splicing or repinning
  • Factory harness is left untouched, so the install is fully reversible
  • OEM-style connectors and correct wire gauge throughout
  • Built in the USA by Boomslang
  • Complete kit: Haltech Nexus S2 ECU plus the matching harness in one order

What's in the Box

  • 1x Boomslang plug-and-play wiring harness (BF29112) for the 2004 Subaru STI
  • Haltech Nexus S2 ECU
  • Haltech air temperature sensor, small thread (M14 x 1.5)

Frequently Asked Questions

Does this kit require cutting the factory wiring?

No. The Boomslang harness plugs into the factory engine harness connectors, so the stock wiring stays intact and the vehicle can be returned to stock.

Which vehicles does HT-651078 fit?

The 2004 Subaru STI with a manual transmission.

Does it need a tune after installation?

Yes. A Haltech standalone ECU must be calibrated for your engine and modifications before the vehicle is driven. Tuned By Shawn offers remote and in-person Haltech tuning. Email service@tunedbyshawn.com with any fitment questions before you order.

For off-road and competition use only. Not legal for use on pollution-controlled motor vehicles.