Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 8 - Jul 13
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
Holley Terminator X MAX Engine Management Systems 550-931TERMINATOR X MAX MPFI W DBW Take control of your LS engine with Terminator X Max! 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 Max features real time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs and
TERMINATOR X MAX MPFI W/DBW
Take control of your LS engine with Terminator X Max! 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 Max 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. Part number 550-931 also has Drive-By Wire Throttle Body control. Terminator X Max 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 MAX has the features and technology you need at a price that won't break the bank!
Features:
- Designed for GM 4.8/5.3/6.0 LS Truck Engines and LS2/LS3 with 58x Crank, 4x Cam and a Drive-By-Wire Throttle Body, with EV6 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.
- 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
- 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
- Recommended Pedal part number - 10379038
- Includes: 58x/4x LS Engine Main Harness - EV6 Injector Harness - DBW Throttle Body Harness - Terminator X MAX ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.
Specs
| Brand | Holley EFI |
|---|---|
| Crank Reluctor | 58x |
| Emission Code | 3 |
| Ignition Type | GM LS 58x |
| Injector Connector | USCAR (EV6) |
| Product Type | Terminator X Max LS MPFI |
| Terminator LS Options | Fuel, Spark, Drive-by-Wire |
| Part Number | 550-931 |
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 1167 reviews
Sort
Product Reviews
★★★★★ 5
Love them
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
I wear a size 11.5 in ladies shoe and these just barely fit. Butttt after I put lotion on my feet and slipped these on and left them on for about 30 mins. It left my feet really soft! They work great as intended. Would buy again
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 31, 2026
★★★★★ 3
Effective but may be uncomfortable
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
I have eczema on my feet and use a prescription cream that I leave on overnight. I often have a problem sleeping in socks but the silicone feels cool on my feet. The only drawback I have is the opening of the socks feel very tight around my ankles making them uncomfortable on me. I wish the opening was a bit more flexible.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on September 20, 2025
★★★★★ 1
Burned my already sensitive feet, too big
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
Feels icky, and the heat gets trapped and literally felt like my feet were being burned by these. The bottoms of these feel prickly and they are way too big. You have to sit still and cannot walk in them.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 22, 2026
★★★★★ 5
Just as good as paraffin wax
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
I might prefer these socks over paraffin wax. They are comfy and very moisturizing. I use these socks once a week to keep the heels and soles of my feet moisturized between pedicures. I rinse with warm, soapy water then hang to dry. They are hard to walk in, but there's a saying printed in the socks that's says something to the effect of "take a break, stay off your feet" lol I love that as a reminder to put my feet up and relax
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 9, 2026
★★★★★ 5
Love these!
Color: Pink & Beige, Size: Small(fits up to size 7)
Love these! As I write this review, I’m sitting in my recliner with these on. I have had other silicone socks in the past and would like to share a few of the things that I have learned.
These fit great! The others were 2-3 sizes too big because you could not order a size. I wear a size 7 women’s shoe. I got the smaller size. I walked around my apartment in my old ones and they got kinda yucky. Now, I sit in my recliner, put them on and chill for a few hours. I now take them off and put in a ziplock bag so they stay nice and clean (no cat hair!). I use them once a week usually on Saturday or Sunday as I’m a working girl. Also, I use Auqaphor before I put them on and put cotton socks on after I’m finished. Your feet will be SO soft. This is not a one and done…I do this every week especially during sandal season! I know this was lengthy and I hope you got some tips.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 25, 2026