you need the SG15 laptop kit
the ECM is a little black box next the battery below the right side support for the overhead guard?

i had one do the same exact thing about 2 months ago
(mitsu FG18K) same system
thats an emissions compliant model
here in the US reverting it would break some laws
idk about up there

after watching it on the laptop i swapped the ECM and it cleared the issue
but then it was breaking up under load occasionally
i went to go look at it but it ran fine for me (figures)
i didnt get back to solve that b4 i quit though and the guy is too far to realistically service him on my own