is it a lock up converter?
is the 4 pin connector connected to the trans on driverside ?
do you have lockup at cruise?
if yes than
is your chip designed not to lock up at WOT? , some dont
if converter is a L/U and chip is programmmed to not lock up ,that might be the answer (turbotweak chips can have this feature )
at steady cruise speed above (45?) you should have lockup even if chip isnt designed to, depressing brake pedal slightly should cause it to unlock and rpms should rise while depressed, if not
check the white switch under the dash in front of the brake pedal , it may have popped back (out of adjustment ) leaving the switch in the open postion ( lockup disconnected),
it may be the TCC solenoid or 4th gear switch in the trans