I have a 1994 S10 Blazer that normally runs really good. The problem I am having is that when it is warmed up, it will randomly stall when coming to a stop. Driving it runs good, good acceleration, smooth and smooth at idle unless it stalls. When it does stall it will not start right away all the time, but if you wait a few seconds it will fire right up. It has the ALDL plug under the dash so no OBDII codes but it flashes the 12 code when I put into diagnostic mode, as it should, no engine codes. It does give a 67 transmission torque converter lock up code, but I don't think it related. Anybody have any ideas?

 

Sounds like the TCC Solenoid is sticking this will cause a stall when coming to a stop. you can try temporarily unplugging it and see if the problem stops.