does any one know if you can change the ecu to perform better.reprogram wise. if you have was it worth the money.hanks
ecu - 6G Celicas Forums
The general consensus about reprogramming the stock ECU is: you will not see much improvement of performance unless you have major modifications done to your engine. By major modifications I mean more then just the basic bolt-on.
theres not much you can do to the 5s motor 
bummer
bummer