great for a stock motor or lightly modified motor. crap for anything close to 1 bar of boost and even worse in USDM trim.
There is a a company called ATS based out of Dallas Ft. Worth they have the capability to ROM tune MR2 Turbo ECUs through TECHTOM using Mighty Map Software.. However the price to have them tune the ECU starts at $750!! Aside from the cost your extremely limited in tunability.. Largest size injectors you can have the ECU remapped for is 550CC which by the way is additional $100 add in their core charge of a whopping $275 and you are now in standalone EMS territory.. (Figure what a fully assembled Mega-squirt with Harness cost) Oh yeah and every re-tune will cost you $150.. Hardly worth it IMO.. This is reserved for the purist who cares not of cost.. Then again you could most likely find a second hand European ST165 programmable rally spec ECU at this price as well..
it's possible to transform most pre-obd2 toyota ECU in a way that allows them to be fully programmable while retaining 80% of the existing components. I have done it for the 86 3s-ge, 90 3s-gte, 91 3s-gte and a few off topic ecu. 88 3s-gte and 88-89 3s-ge are in the way at a very low priority rate. nomad here on st162.net uses one. an 86-87 ECU
