Use that and this: https://www.car-part.com/
I was able to find compatible ECU/DME's for less than $1000... If you see one that matches, snatch it up as quickly as you can after doing some due diligence to make sure it's actually one that can be used for the MK5 Supra (i.e. ask for the VIN to...
It seems like breaking through 500whp is challenging with JB4 based on all the posts in this thread.
What is the bottleneck? DI fuel delivery? Turbo size?
It seems like all that matters around here are cold hard facts and numbers which can be useful. However, empirical data shouldn't be discounted when it comes to these things. Not everything has to be so black and white :cool:
After doing all the checks above and the CEL is still there, I'd contact AA if it's brand new to see if they'll swap it out for a new one under warranty.
If it's used, they had a batch of defective DPs a while back so I would contact AA to see if your DP serial number was part of that batch...
What are your power goals? With other power mods like flex fuel, DP, PI, upgraded turbo, and/or intake manifold, 600+ whp is absolutely attainable with just BM3.
Cloning doesn't seem all that necessary anymore with new features being unlocked by BM3 and MHD on every release. As you said, most people will get everything they need without a clone, ecutek, and tune. There are others who may want to preserve their factory ECUs for state inspection/smog check...
According to Femto, factory DME checksum is preserved/saved as part of the unlocking process.
This is in the context of bench unlock and using BM3 CustomRom. I would agree that the safest and full proof way to pass would be cloning.