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Description
Holley Terminator X Engine Management Systems 550-903TERMINATOR X MPFI, LS1 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
TERMINATOR X MPFI, LS1
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 LS1/LS6 engines with 24x crank reluctor - with EV1 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.
- On-Board 1bar MAP sensor, is perfect for N/A or Nitrous engine combos. If your combination requires a 2+Bar, we recommend GM 12592525, and our adapter part number 558-416.
- MAP Sensor vacuum hose adapters (1/8th – ¼ and 3/16ths)
- 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
- 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!
- 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
- 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 - EV1 Injector Harness - Terminator X ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.
Application
- 1998 - 2002 Chevrolet Camaro
- 1997 - 2004 Chevrolet Corvette
- 1998 - 2002 Pontiac Firebird
Specs
| Brand | Holley EFI |
|---|---|
| Crank Reluctor | 24x |
| Emission Code | 3 |
| Ignition Type | GM LS 24x |
| Injector Connector | Jetronic / Minitimer (Bosch) |
| Product Type | Terminator X LS MPFI |
| Terminator LS Options | Fuel, Spark |
| Part Number | 550-903 |
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
4.4 ★★★★★
Based on 19 reviews
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Product Reviews
★★★★★ 3
Nice wedge pillow but not enough...
Color: Cool Grey, Size: 24x24x12 inch
It came compacted and when I opened it expanded almost immediately, maybe took like 20 minutes to fully decompress. Its soft and comfortable and the cover is really nice. But it does have a strong chemical smell, which is normal for this kind of brand new memory foam, I just put it on a table with a window open near it and after maybe 24 hours the smell was almost completely gone.
The problem is that I bought this to have a elevated position when sleeping but the 30° are just not enough for me. I wish it was at least 45° but I could not find any pillow with that amount of degree... it's either 30° or like 75° in the other position. At the base of the pillow there is a little ridge that is comfortable for the lower back but makes me slide down in the middle of the night so I end up almost laying flat with my neck on the base ridge. With my slim build my lumbar area gets some nice support but makes my head almost have a "fall backwards" sensation, I like having my neck have a "push-forward" position with my pillow, but when adding another pillow to try and get to a comfortable position it only makes me slide down even more... :/
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Reviewed in the United States on November 6, 2024
★★★★★ 5
Very firm and durable
Color: Cool Grey, Size: 24x24x12 inch
worked great for husbands surgery recovery. Very affordable, firmness was great, looked nice on the bed and also used it for the grandkids when they were watching a movie. Moved around with ease. Didn't use it to sleep with all night though. He could only make it half the night but that wasn't the pillows fault. It was the cast on his arm. Definitely did its purpose after surgery and the need to sit up in bed more. highly recommend
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Reviewed in the United States on May 12, 2026
★★★★★ 5
Sasstie Wedge Pillow
Color: Cool Grey, Size: 24x24x12 inch
Perfect. I used it when I was recovering from hip surgery. Relieved a lot of pain in my hip and knee at a time when I needed relief.
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Reviewed in the United States on May 30, 2026
★★★★★ 5
comfortable and firm!!
Size: 57 Inch, Color: Light Grey, Size: 57 Inch, Color: Light Grey
this pillow is huge i’m 5’8 and it’s perfect, as soon as i laid down it relived pressure in my back, i get hot fast and you can feel the cooling silk like texture, it’s weighted aswell, as soon as i opened it, it fluffed up an it’s been about 2 hours since and it’s already huge, it says 24-48 hrs to fluff up fully but idk how much bigger it could get lol it’s definitely worth the few extra dollars
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Reviewed in the United States on April 14, 2026
★★★★★ 5
I must have for pregnant women! Definitely helps sleep and comfort for sleeping!!
Size: 57 Inch, Color: Light Grey, Size: 57 Inch, Color: Light Grey
I do love this pillow, it does take up a lot of space on my queen bed! But when I wrap my legs around the pillow, it gives me much relief on my back! It also has basically a built-in pillow so you don’t even need to use a pillow! I love that I was able to unzip the outer material and wash it! You can use it to sit up and support your back, and when the baby comes, you can use to help with feeding! sometimes I have to turn it completely on the other side if I want to turn over, it’s big!! heavy! Very soft! Not flat at all! Firmness is great! Height is great! I highly recommend! I’m also five months! i got it about 2 months ago!!
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Reviewed in the United States on February 13, 2026
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