Sxqddz CAN Bus Y-Splitter Cable MA558-465 for Holley ECUs — Shielded 4‑Wire, Compact Plug‑and‑Play

The Sxqddz MA558-465 CAN Bus Y-Splitter is a compact, shielded four-wire adaptor that lets you connect a handheld and a laptop (or two CAN devices) simultaneously to compatible Holley EFI units.

This compact adapter is engineered for engine management setups that use the CAN bus on Holley systems such as Sniper, Terminator X and Dominator. Designed as a direct-fit extension harness, it simplifies connecting diagnostic tools, programming devices, and handheld controllers without altering the main ECU harness. Built with a shielded four-core design, the cable helps maintain signal integrity across connected devices while offering a tidy, foldable form factor for vehicle installations.

How does the Y-splitter help when tuning or diagnosing my Holley ECU?

The splitter allows two CAN-capable devices to share one ECU CAN port so you can monitor and program simultaneously. This removes the need to constantly swap cables during tuning sessions or live diagnostics, saving time and reducing wear on connectors.

• Connects a handheld and laptop to the same CAN port at once
• Makes live tuning and simultaneous logging effortless
• Prevents repeated plug swaps that can damage pins
• Compact form keeps wiring neat inside the engine bay or garage

Is the MA558-465 compatible with my Holley Sniper, Terminator X or Dominator?

This adapter is made specifically to work with Holley EFI family units listed and is interchangeable with part numbers 558-465, TERMX-Y6 and TERMX-Y-6. It plugs directly into the ECU harness without modification for a true plug-and-play experience.

• Fits Holley Sniper, Terminator X and Dominator ECUs
• Manufacturer part MA558-465; also sold under the listed interchange numbers
• Plug-and-play installation—no splicing required
• Ideal as an extension or diagnostic splitter in workshop setups

What are the cable construction and usage precautions?

The cable uses a shielded four-wire construction to reduce electrical interference and preserve CAN signal quality. When updating ECU firmware, remove the splitter and attach the updating device directly to the main harness per manufacturer guidance to ensure a reliable update path.

• Shielded four-wire design for improved noise rejection
• Compact, foldable cable for easy routing and storage
• Durable build for long service life in garage or track environments
• Unplug the splitter before firmware flashing; connect updater directly

How easy is installation and what comes in the package?

Installation is straightforward: plug each end into the respective CAN sockets—no tools or wiring changes are required. The package contains one CAN Bus Y-splitter cable and arrives ready to use for diagnostics and tuning sessions.

• Simple plug-and-play hookup with no splicing
• One MA558-465 Y-splitter included per package
• Minimal routing required thanks to compact size
• Tip: verify part number compatibility before ordering

Who is this for: The Sxqddz MA558-465 is aimed at professional tuners, performance shops, and DIY enthusiasts who use Holley EFI systems and need a reliable way to connect multiple CAN devices at once. If you frequently switch between a laptop and handheld for logging, programming, or monitoring, this splitter keeps your workflow efficient and your main harness free of repeated wear.