Any updates? Having a similar issue after having a tune from a reputable person. I was not towing anything just driving an 83 mile one way trip each way. I had transmission stuck in 4th and it threw the p0741 with no cel. Then p0741/with cel came on on the return trip. And checking the cel it was for the p0741. Everything I am finding is pointing to the torque convertor. Just did pan service and nothing of was substance found.