Suddenly my 1JZ cuts fuel when given over half throttle. Dies and wideband reads full lean. Once it drops under 1700 rpms, it returns to normal. Drives normally as long as you don't give it more than half throttle. My ECU went bad and I had it repaired by Driftmotion. The IACV still doesn't work and the ecu won't store codes but it otherwise ran fine. Where should I start looking to diagnose this?