I've been trying to search for an answer to this for a while but I haven't been able to find anything on the site. Does anyone know if it would be possible to use a USDM supra turbo ECU when doing a GTE swap into our cars? I have to do emissions in my area and from my understanding OBD readers cannot read the Japanese ECUs. If the swap could be done with a US turbo ECU thats OBD2 then the computer could read emissions on the car. I also read on the forum that Toyota does not encode the VIN into the ECU so using an older model year would not be a problem. Forgive me if this is a dumb question or if its been covered before. Any info on this would be greatly appreciated thanks!

 

You will have to do extensive wiring to get the ecu to work and you will still have a check engine light on for some of the circuits not found on the Supra ecu. Easier o find a county that does not do the OBD2 scan.

Or run a piggyback on the stock GS computer.

 

Thanks for the response Letsride. You seem to know everything related to the wiring on GTE swaps. That was too easy a solution to passing emissions so figures that that would be the case. I'll probably just garage it in a county that doesn't do emissions. I've heard a lot of mixed opinions about running a piggyback.

 

Piggybacks are not ideal and if you are going to daily the car just use the aristo ECU. You can get around the emissions stuff......possibly get a waiver depending on your DMV up there. And yes.....I have done extensive wiring on the 2j platform.

 

Lets talk about this. I have thought about it before but decided to pursue other avenues. but. from what i can think of right off the bat, you'd have to 550 cc injectors along with the usdm maf sensor. also you'd have to wire in a downstream oxygen sensor for catalytic converters. than run those or a trick device. more importantly, you'd have to somehow figure out the egr stuff. i'm under the impression the usdm supras run egr valves. it all seems like a lot. but once its done you can rock a obd2 friendly 2jz.

 

It can be done, as I'm currently doing a 98 MKIV USDM 2JZGTE swap into my 03 GS300. I have a 98 MKIV USDM TT Auto ECU and got a custom wiring harness made by Tweak'D Performance ( work of art). You would need the USDM TT transmission as well. Very expensive swap, but needed if you want to pass emissions as I will be doing in Atlanta, GA. Gerrb/Gerry has been helping me with my parts/swap, so I've got the best on the job I plan to start a build thread as soon as I have the rest of the parts to do the swap. FMIC, return fuel line, small stuff as all the big pieces are already in my hands.

 

The downstream O2 and the egr can be eliminated easily without throwing a code. The main engine functions can be sorted fairly easily as it only takes 7 wires to run the GTE. However there are several things that the GS has ABS AC etc that will not be an easy transition to to the Supra ECU.

 

Yes please start a build tread and let us see the progress and how that tweak harness works out for you. Gerry is a great source of parts and a wealth of knowledge on anything 2j but I dont think he has ever attempted that specific swap into the GS. But we are here to help if you run into issues. He can tell you what I have in my stable....

 

I know there was also a thread by JeffTsai where he built something to spoof the stock ECU into thinking it was running the engine when it was really being controlled by a standalone. I know that's a lot more complicated and expensive since then you have to pay for a new ECU and tune but it would let the car pass emissions. Its definitely easier to say its just garaged somewhere else. Not to mention legality

 

Will do. I will be meeting up with Gerry this weekend to see what's left to piece together. Appreciate the support...hoping I will not need it though

 

Some functionalities of the 2nd Gen GS300 , just like the IS300 , are accessed only through the MPX network (communication system) that connects to the stock ECU . So one needs to do some work / wiring just like we did on an IS300. You take out the stock ECU and some functionalities won't be available and warning lights will be on. Keep in mind also that on the 2nd Gen GS300 , the 1998-2001 are different from the 2002-2005 when it comes to their stock ECU wiring.

Haven't inspected Jason's tweak harness fully yet. I hope it was done right as he specifically mentioned to them that he wanted all GS300 functionalities to work .

Jason - start that build thread . Snap pictures of that pretty GS300 of yours . You basically got 95% of what you need to get that GS300 USDM 2jzgte swap going . I can swing by your place to help you assemble that engine one afternoon this week. Glad to be of help buddy. For your monster SC300 , bring those parts from your buddy's place to yours so I can come and help you get it going too whenever I am free and am up there North.

Peter - what's up buddy , got that mkiv and mk3 all working good now ?

 

Gerry exactly.

The tweak harness was my first point of concern and you know thats why we do all of ours in house now. He tends to "forget" to do a lot of stuff on them.

As far as warning lights etc, you are correct and there currently is no work around for the MPX network issues. Also, how is he going to handle the fuel gauge issue?

And yes.....I'll have to update you on all of the cars. PS:Theres one now with a twin turbo LS3 in it!

 

wow , twin turbo LS3 .. on what car ?

Jason's objective is to get the odbii to work without error codes so to pass emission which I don't see any problem since he is using all 97-98 USDM specs 2jzgte .... all stock.

It won't be much different from an IS300 of a friend I did help do the swap and more likely the same situation on an SC430 for which I am planning to do a 2jzgte swap so I have a convertible 2jzgte and complete my SC collection . Got the car , just waiting for the 70k engine to konk out if ever it will that is why I am letting my youngest son use it for now. You know how young kids are, all they know is get the key and drive .

 

MK3 Supra!

 

Yea the car should pass and that install should be fairly straightforward. However I dont want anyone reading this thinking that all of the systems in the car will be fully functional.....because they wont! But hes got the best guy working with him.......hes in excellent hands....