Can anyone give me the pro's and cons of using stand alone engine management like motec or ecutec as opposed to using the rs wiring, the wrx wiring, and the wrx ecu with accessport reflash? How hard is it to install standalone engine mangement? Would most of the rs wiring still have to be changed? I guess i dont know what the standalone completely replaces. Anyone here used standalone on a conversion before? Thx.

honestly its all about the drivability and finding some one with the skills (and that you trust to program the standalone)

i have a tec 2 it drives it races it was tuned by me .. driving it around town is ok but its work

you get two things when you use wrx wireing+ecu in a swap
leagality (perfectly leagle even in CA) to swap a newer motor into an older car
driveability.. you also get the ecu trouble codes which can be quite usefull

i seriously hope you are not considering swapping a wrx engine into a 2005 - don't do it

For me, the big consideration in that equation is emissions. I live in an OBD-II compliant county. As such, I favour a WRX harness and ECU for swaps. Then tune by ECUtek or Street Tuner.

But if I were clear of emissions, I would just wire in a piggyback. We used an E-manage on a swap I did recently, and it is a pretty good little system. I didn't end up tuning the E-manage, but was still pretty impressed by it's capabilities...