AEM's 02-07 WRX & STI Plug and Play Engine Management System (EMS) is a user-programmable full standalone Engine Control Unit (ECU). Installing an AEM EMS into your WRX or STI is simple, plugging directly into the stock wiring harness in the passenger kick panel- no wiring, spicing or soldering required!

The advanced AEM Windows-based EMS programming software makes tuning, injector scaling, and sensor calibration a simple process. Unique user-defined templates make tuning the AEM engine management system even simpler, as you can establish quick keys to streamline the tuning process. While professional tuning is required, AEM conveniently includes base maps, to get the car running, and use as a jumping off point when initiating the tuning process.

The AEM EMS standalone ECU for the WRX & STI is infinitely adjustable, and with the large variety of optional enhanced sensors (i.e. MAP, EGT, IAT, etc.), experienced tuners can set your Subaru up for advanced, more complex features that will unlock the full performance potential of your Subaru. When used with the optional AEM integrated wideband or an external UEGO wideband (sold separately), the AEM EMS has the added capability to auto-tune fuel curves. The EMS is truly an advanced achievement in tuning performance that offers professional features and functions unmatched by less expensive reflash and piggyback systems.