I am in a process of converting my '97 SC300 with R154. I know all OBD 1 cars can retain the auto ECU without the CEL light coming on.

Different story with OBD II though, If I keep my auto ECU I will have a CEL light. In order to fix the CEL light, I need an OBD II manual ECU ( I can source one from 1996 manual SC300). Now here are my questions:

1. Will a 1996 manual ECU will work on my car or I have to get one from an MKIV?

2. If the 1996 ECU will work, is it ideal to use this ECU for 2JZGTE non-VVTI swap?

 

I am pretty sure the 96 ecu will work on the manual swap(you may need a 97 specific, but I doubt it)...Even so, the 2JZ-GE ecu won't run the 2JZ-GTE engine. The only option to run a manual, OBDII swap without a CEL would be a USDM Supra ECU. That also means converting to MAF, or at least a VPC. It may also involve some EGR trickery to prevent a CEL if you are running a JDM non-EGR swap. Regardless, there is going to be some wiring involved.