I know this thread is a little old, but I am having similar problems as the OP. Doing 4wd, WOT launches my converter will not lock until 4th gear, and seldomly 3rd. I'm looking into getting a lockup controller. Just wondering though, I know you can use the scan tool to activate the TCC solenoid, would it be ok to do this on a WOT run? Or would it still not lock?