Holley Terminator X (550-903, LS1/LS6 24x) ECU
The Holley Terminator X (550-903, LS1/LS6 24x) is an entry-level wire-in engine control unit (ECU) from Holley. It has 8 injector and 8 ignition outputs, support for up to 8 cylinders, 1 onboard wideband lambda input and knock control. List price is US$1,600. 11 sellers list it from US$1,499 to US$2,111.
Prices checked . Specs from Holley's published data.
Key specs
DBW = drive-by-wire throttle channels · λ wideband = onboard wideband lambda (oxygen sensor) inputs · CAN = controller area network buses.
Features
- ✕Drive-by-wire
- ✓Onboard wideband
- ✓Knock control
- ✓Flex fuel
- ✕Traction control
- ✓Launch control
- ✓Boost control
- ✕Gearbox control
- ✓Onboard logging
- ✕Ethernet
- ✕USB
- ✓Built-in display
✓ published · ✕ not offered · ? not published. Some features, like traction control and launch control, mean different things by brand. See the glossary.
Details
- Highlights
- Self-learning fuel, 3.5in touchscreen handheld, engine-specific harness kits; high-Z injectors only
- Software
- Holley EFI V5 software, free
- Logging
- onboard (size not stated)
- Links
- Product page ↗Price source ↗
- Tuning
- Find a Holley EFI tuner with a dyno
- Maker
- Holley: history, software and every model
Where to buy the Terminator X (550-903, LS1/LS6 24x)
11 sellers found
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Prices as shown on each seller's site on , in their own currency, converted at 14 Oct 2026 rates. Shipping, import duty and tax vary. Check with the seller before you buy.
