WRXLink (04) - WRX104X

Easy to install. Affordable. Reliable.

The Link G4X PlugIn ECU transforms your WRX into a precision-tuned performance machine. Enjoy the latest in engine management technology, fitted directly into your OEM enclosure with no loom modifications required.

Choose the Right Model – Pin Check Required!

The fastest and most reliable way to confirm you need the WRX104X is to check pins A1–A3 on the OEM connector:

• Pins A1–A3 have wires → You need the WRX104X (this listing, 224-4000)
• Pins A1–A3 are empty → You need the WRX107X.

WRX104X mostly covers 2004–2006; some late-2006 cars require the WRX107X, so this check is essential.

Vehicle Compatibility

• Designed for WRX V10 EJ25 (2.5L) 2004–2007
• Manual transmission only
• Suits GD/GG chassis with electronic throttle
• Not suitable for GR/GH/GE/GV hatchback or 3rd generation WRX

Model breakdown:
WRX104X → Mostly covers 2004–2006
WRX107X → Mostly covers 2007 and some late 2006

Why Choose Link G4X?

• Factory fit, motorsport power – installs in the OEM case with world-class tuning flexibility.
• Plug & play – no wiring loom alterations for supported models.
• Confidence & reliability – proven hardware and software, trusted by tuners worldwide.
• Serious features – advanced boost control, antilag, launch, knock control & more.

G4X PlugIn Key Features (where applicable):
Up to 6D fuel and ignition mapping
Precision closed loop cam control (four cam, independent control)
Sequential fuel delivery
Digital triggering, all OEM patterns
OEM idle hardware supported
5D boost control with three switchable tables
Motorsport features - antilag, launch, flat shift
Continuous barometric correction (on board)
CAN port
QuickTune - automated fuel tuning
Individual cylinder correction
USB tuning cable included
Stats recording into on-board memory
Gear compensations for spark, boost and fuel
Real time selectable dual fuel, ignition and boost maps
Sync and crank sensors can be a combination of Hall effect, variable reluctance or optical
Boost control referenced to gear, speed or throttle position
512 mega bytes data logging memory within data storage unit
Staged injection
Knock with "windowing"

There are two different options for the expansion connectors, depending on whether your ECU is the 2004-2006 ECU or the 2006-2007 ECU.

2004-2006 ECU
The following expansion connector inputs/outputs are provided:
Blank AN Volt 11
An Temp 4 Temperature sensor input
Blank No function
Blank AN Volt 12
Blank No function
Blank No function
+5V Out Low Current +5V Supply
Gnd Sensor Ground Only


2006-2007 ECU
The 2006-2007 V10 ECU contains an 8 pin expansion connector.
The following expansion connector inputs/outputs are provided:
Aux 11 Auxiliary Output
An Temp 4 Temperature sensor input
Aux 12 Auxiliary Output
Volt 11 Analog 0-5V input
Aux 13 Auxiliary Output
DI 11 Digital Input
+5V Out Low Current +5V Supply
Gnd Sensor Ground Only

Download Manual

Click here to download the full Specifications PDF.