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- USA
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Ships within 48 hours · Estimated delivery Jul 14 - Jul 19
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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
4.8 ★★★★★
Based on 1099 reviews
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Product Reviews
★★★★★ 5
The best way to tire your dog out in the dark
Size: 25in
My 7 month Golden Retriever puppy has way too much energy. And I go to work in the dark, and come home in the dark. This was the solution.
First of all if you get this, I suggest a UV flashlight to charge it. Most of these phosphors for glow in the dark items have very strong optical absorption in the UV, and the UV will charge both the ball and the launcher in seconds. I shine the light at the launcher with the ball in it, since you can then see where the launcher is when you are trying to load the ball. I use this UV flashlight, which takes qty=3 AA batteries.
https://www.amazon.com/gp/product/B01A5KLUG2/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
I have never used a launcher before and I learned it within about 10 throws. It is easy to have a basic competence. I live in a suburban area and I send the ball across front lawns, trying to avoid the street, or hitting my neighbors parked cars. I can consistently do this now with the launcher, which is a big improvement over the old tennis racket and ball routine.
I got the 25" medium ball launcher, which also works for tennis balls. The scoop goes easily over the Chuck-it balls. My older dog is not taking to it, since he was trained to sit and give the ball. This works better if you have the dog drop the ball so you can scoop it.
The glow in the dark ball has 2 holes (think wiffle) that have a low pitch whooshing whistle as you toss it. This is great for my puppy who gets easily distracted as the glowing ball and the noise it makes really helps him propery mark it. Overall I think the dog retrieves better in the dark as there are fewer distractions, and I feel better about the dark for retrieving since there is no traffic early in the morning (both foot and auto). The ball has some squish to it and the pup loves to chew on it as he brings it back. I do not let him play with it when we are not retrieving...better for him to destroy his chew bones and ropes. It took him about 5 tries to get the hang of picking up the new ball. The older dog (13yr old golden) does not like it and only goes for tennis balls.
I can tell already this is my puppy's favorite toy ever. I put it up out of reach across coat hooks in the entryway, and that pup will sit there staring at it, then at me, then at it hoping that I will go out and use it. With bounces and rolls and the puppy missing the grab this has gone 100-150' across 3 front lawns. I am looking forward to giving it a go in the park on the weekend.
Main problems with the pup now are he likes to parade around me with the ball when he comes back, then lie down and try to give it a proper chew. If I use my launcher to pick it up, I have to put my foot between him and the ball since he will try to get it back fast. Overall this launcher means faster pickup, faster release, more accurate release, good distance, and a better run per time allocation than the old tennis racket and ball routine.
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Reviewed in the United States on January 29, 2020
★★★★★ 5
Chuck a Glowing Ball
Size: 18in
This baby ball checker is good for a medium sized dog because of the size of the ball which glows in the dark. It is a handy feature for playing with the dog at night. It is fairly priced, durable. It doesn’t squeak and is not made to be chewed. F your dog likes to run around after balls this should be good for you.
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Reviewed in the United States on December 19, 2025
★★★★★ 5
This is the one to buy if you wish to get the most out of your arm and give the most to your dog
Size: 25in
The pro series must be made of a higher quality plastic than the original version, as the stiffness of the Pro series chucker allows for way more distance with less effort and greater control (for line drives, high arching throws, and bouncing grounders). Your dog will thank you endlessly for choosing the Pro over the regular (original) models. I have an old legacy original model that I keep in my truck for road trips that works reasonably well, though not as well as the Pro version. Here’s the thing: Before purchasing the Pro model, I ordered another original version (same length, 25”) and was instantly disappointed in how soft and leverageless was the chucker. Either my (original) original one (a Goodwill find) stiffened over the course of years, or the newly made “original” versions are now made with a softer kind of plastic. This soft chucker led to a disastrous throwing experience for my dog. Instead of thrilling at each throw and the lightning fast response of my dog, I hated every throw. I returned the “original” model and ordered the only 25Pro model I could find at 25” on Amazon… a glow in the dark version. There may be a benefit to the glow in the dark feature, but I don’t really care about that. It’s the leverage that I wanted and that’s what I got with the Pro version 25”.
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Reviewed in the United States on August 22, 2025
★★★★★ 5
Great design
Size: 25in
Ball is very durable yet soft. Whistles when you throw it and goes very far. Handle is ergonomic with a nice rubber grip. Both the launcher and ball glow green in the dark. My GSD loves it. She’s 75 lbs and the medium ball is fine.
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Reviewed in the United States on January 23, 2026
★★★★★ 5
Husband and dogs highly approve.
Size: 25in
My husband wanted us to replace one from a different company that broke. It had to have a glow in the dark ball, since he sometimes plays fetch with the dogs at night. He couldn’t love this more. Says it’s so much better than the other one, the whole thing glows in the dark and it throws farther. According to him, it’s the best ever.
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Reviewed in the United States on August 9, 2025
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