Checked the ECU, it's 5VK-8591-01.

Took it out Yesterday, with CO up 8 places & AIS done. Seems to be better. Have increased the CO up another 2 to make that 10 in total. Any limits on that increase? Still getting a lot of back fire. But that doesn't really! worry me too much. It's more the fuel delivery.
Will get back on how this runs again.