If the dash lights stay dark or flicker after the stall, ignition switch.
If the dash lights come on after the stall, could be the fuel pump relay. Common issue with Honda's.
Yes, if it's a used car install the Magnefine in the return line to catch dirt that's dislodged from the cooler before it enters the transmission.
If it's a fairly new car (or if a fairly new radiator), install on the supply line to catch dirt before it becomes lodged in the cooler.
Dave
Honda has a different procedure from many other makes to check the ATF level. Always check ATF with the engine off, but with the transmission fully warmed up.
Dave