Haltech Nexus S3 ECU & Toyota Celica GT 2000-2005 Plug 'n' Play Adapter Harness Kit (HT-651026)

This Tuned By Shawn plug-and-play kit (HT-651026) pairs the Haltech Nexus S3 ECU with the matching Boomslang adapter harness (BF29056) for the 2000-2005 Toyota Celica GT (7th-generation Celica, 1ZZ-FE engine) with a manual transmission. The harness plugs into the factory engine harness where the stock ECU connects, so the Nexus S3 takes over full standalone engine management with no cutting, splicing or repinning.

Vehicle Fitment

• 2000-2005 Toyota Celica GT (manual transmission)

Boomslang part number: BF29056. 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 S3 ECU, and the Boomslang harness is built for its connectors.

Features

• Vehicle-specific plug-and-play fitment for the 2000-2005 Toyota Celica GT
• 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 S3 ECU plus the matching harness in one order

What's in the Box

• 1x Boomslang plug-and-play wiring harness (BF29056) for the 2000-2005 Toyota Celica GT
• Haltech Nexus S3 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-651026 fit?

The 2000-2005 Toyota Celica GT 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.