You can't really tune a stock ECU, unless you fit a ROM, interceptor, piggy back or a replacement ECU.

Any of the places who normally tune these could sort it out.

All-Star Garage, Revlimit Motorsport, Maximum Motorsport, Race Torque are 4 places to consider straight away.

Contact details:
http://www.perth-wrx.com/vb/mechanicals/6775-perth-workshops.html