Introduction. Subaru's EJ207 engine was a 2.0-litre horizontally-opposed and turbocharged four-cylinder engine. For Australia, the EJ207 was first offered in the Subaru GC Impreza WRX STi in 1999 and subsequently powered the Subaru GD Impreza WRX STi. A member of Subaru’s Phase II EJ engine family, key features of the EJ207 engine included its: