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Ships within 48 hours · Estimated delivery Jul 7 - Jul 12
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Description
Holley Terminator X Engine Management Systems 550-904TERMINATOR X MPFI, 4. 8 6. 0 EARLY TRUCK Take control of your LS engine with Terminator X! Don't settle for a junkyard ECU with a cumbersome tuning interface when you can have complete control of your engine, self learning fuel strategies and the proven, race winning technology of Holley EFI at a budget friendly price! Terminator X features real time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs
TERMINATOR X MPFI, 4.8-6.0 EARLY TRUCK
Take control of your LS engine with Terminator X! Don't settle for a junkyard ECU with a cumbersome tuning interface when you can have complete control of your engine, self-learning fuel strategies and the proven, race-winning technology of Holley EFI at a budget-friendly price! Terminator X features real-time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs and outputs. The inputs and outputs are ideal for electric fans, boost control solenoids, progressive nitrous control, and much more. Terminator X comes fully loaded with base maps for common LS engine combinations to get you out of the garage and on the road/track fast. The 3.5" touch screen LCD handheld contains an easy to use calibration wizard as well as tuning and gauge display functions. Also included is Holley EFI's industry-leading, easy to use software suite that allows full laptop access for advanced users. Whether you are building a budget beater or a boosted race car, Terminator X has the features and technology you need at a price that won't break the bank!
Features:
- For GM LS Engines with 24x crank reluctor and Multec 2 Injectors
- Real-Time fuel map learn, takes the guess work out of tuning your base fuel table.
- High Impedance Injector Drivers will safely power most Stock LS injectors, and Holley EFI Injectors. Injector support chart provided in the instructions (Will not control Low Impedance Injectors)
- All of the new Terminator X systems utilize the Bosch LSU 4.9 wideband to relay AFR information to the ECU for accurate reading and precise tuning control.
- MAP Sensor vacuum hose adapters (1/8th – ¼ and 3/16ths)
- 4 Outputs – Ground, PWM - , for accessories such as; fans, boost control, nitrous control, IAC Kit, and More
- 4 Inputs – 12v, Ground, 5v, and Frequency, for things such as additional pressure sensors, or activation triggers for nitrous activation, or a trans brake
- Boost Control – Boost vs Time, Boost vs Gear, Boost vs RPM, Boost vs Speed, Boost Safeties
- Nitrous Control – Single Channel of Wet or Dry, Progressive or Non-Progressive, Rich/Lean Safeties, and target Closed Loop AFR
- On-Board Diagnostic LEDS for: ECU Power – Engine Run – Wideband Status – TPS Calibration – Crank Signal –Cam Signal. Allow you to identify any Critical engine issues at a glance
- Advanced Tables – 4x 1D Tables, 1x 1D per Gear Table, 4x 2D Tables, 1x 2D per Gear Table, can be used for any custom tables you can dream up, such as Flex Fuel Sensor Offset Table, or a custom fuel or oil pressure safety!adjustable through included 3.5” f
- The included 3.5" Touchscreen Handheld contains a calibration wizard, that allows you to quickly build a base tune for any LS engine. Additionally the handheld provides internal data-logging and a fully customizable gauge display.
- The compact ECU size allows you to mount it virtually anywhere. Remember, diagnostic LEDS must face up!
- Plug and play compatible with more Holley EFI accessories such as; analog style gauges, shift lights, various modules, and coming soon, 12.3" digital dash support!
- Free EFI Tuning Software for complete control of your Terminator X power plant
- Includes: 24x LS Engine Main Harness - Multec 2 Injector Harness - Terminator X ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.
Application
- 2003 - 2006 Chevrolet Express
- 2003 - 2006 GMC Savana
- 1999 - 2006 Chevrolet Silverado
- 1999 - 2006 GMC Sierra 1500
- 2000 - 2006 Chevrolet Tahoe
- 2000 - 2006 GMC Yukon
- 2002 - 2007 Chevrolet Avalanche
- 2002 - 2006 GMC Yukon XL 1500
- 2003 - 2005 Chevrolet TrailBlazer EXT
- 2003 - 2004 Isuzu Ascender
- 2003 - 2004 GMC Envoy XL
- 2003 - 2004 Chevrolet SSR
- 2004 Buick Rainier
- 2002 - 2007 Chevrolet Silverado 1500
Specs
| Brand | Holley EFI |
|---|---|
| Crank Reluctor | 24x |
| Emission Code | 3 |
| Ignition Type | GM LS 24x |
| Injector Connector | Multec 2 |
| Product Type | Terminator X LS MPFI |
| Terminator LS Options | Fuel, Spark |
| Part Number | 550-904 |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.5 ★★★★★
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Product Reviews
★★★★★ 5
helped treat my sore neck
Color: White-cooling Basic, Size: Camping Pillow(Pack of 1)
This pillow — after dialing in the right amount of shredded foam — has greatly helped my sore neck. Initially, I had to remove some foam. Then I gradually added foam until it reached optimum comfort and support.
It is also CPAP-friendly — especially when I position my head near the pillow's edge. (I am a left-side sleeper.)
I like the travel size because I use a bulky hugging pillow to ease stress on my shoulder and elbow. That makes my side of the bed feel cramped if using a larger head pillow. A smaller pillow is easy to flip end-to-end in the middle of the night.
I have spent lots of money on pillows over the years, but this is the best I've ever had for relieving [1] neck pain and [2] CPAP mask seal problems. Very comfortable, supportive, and affordable.
I did not notice any unpleasant smell — and I am usually sensitive to that kind of thing.
Would highly recommend.
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Reviewed in the United States on May 7, 2026
★★★★★ 5
Love them!
Color: White-cooling Basic, Size: Queen(Pack of 2)
Love them! After 10 years with our MyPillows, they finally lost their fluff. The reviews I read of the MyPillows of today were not good; they didn’t have as much filling as they used to. These pillows remind me of how fluffy our new MyPillows were 10 years ago!! You sink right into them and can mush them however and they stay. These are way cheaper than the Coop and it’s the same concept; add or remove the filling as needed. The cooling side is a huge plus too! You won’t be disappointed with these pillows!
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Reviewed in the United States on May 22, 2026
★★★★★ 5
Cooling fabric is Just what I needed
Color: 03-black, Size: 20" X 26" (Pack of 4)
I'm a hot sleeper. These cooling pillow cases are fantastic. It has ended soaked pillow cases. I paired these with waterproof pillow cases for extra pillow protection. I now sleep cooler and wake up dry. I also toss and turn less and wake up less frequently hot, sweaty and uncomfortable and I can sleep though the night. I don't need to flip my pillows over because of sweat. Both sides of these pillow cases have arc chill cooling fabric. They're soft, silky, breathable and comfortable to lay my head on. The colors to choose from is a wide selection. These look great on my king size bed. I love this fabric so much that I upgraded all of my pillows and blanket sheets to cooling fabric. I'm sold on these. The zipper is premium, sturdy and durable. My pillows fit perfectly on these cases. The cooling material is top notch high quality to me with great craftsmanship. I liked these ones so much that I bought more and plan to again. My partner seen and felt these and immediately went online to buy some blankets to go with the pillow cases I gifted. I also bought my son these and a few cooling blankets. These work best with a fan or air conditioner. Highly recommended and you won't regret this purchase if you're a hot sleeper to profusely sweating during sleep.
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Reviewed in the United States on May 10, 2026
★★★★★ 5
Cool and comfy!
Color: 01-grey, Size: 20" X 26" (Pack of 2)
Very comfy and cooling. Great for hot sleepers!
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Reviewed in the United States on June 3, 2026
★★★★★ 5
keeps pillow secured and cool
Color: 05-purple, Size: 20" X 26" (Pack of 4)
just what I was looking for. A cooling pillow case with a zipper! my regular pillow cases slipped off my pillows So annoying. Now my pillows are staying put zipped in. so soft and cool. no more wrestling with the pillow case while trying to flip my pillow over trying to find a cool spot.
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Reviewed in the United States on May 7, 2026