I have a auto 1jz converted to manual but still running the auto ECU. I dyno tuned the car about a 2 months ago, but I recently been getting a Lean to rich spot around 5800-6000 rpm. Now my tuner said it's the Auto Ecu shift limiter ,on the Data logger you can see the injector duty cycle go lean then a sudden rich spike. I used a manual ECU but the check engine light came on DTC 42 speed sensor so I didn't tested it out. My cable is broken and I just ordered 1 from Driftmotion. The other funny part is that the Auto ECU never threw the check engine.