92 Firebird Stalls 3.1L, Auto, Air

Wife’s daily driver often stalls when coming to a stop. I changed MAP, TPS, Fuel filter; Reputable mechanic changed IAC, Plugs, Wires, Cleaned Throttle Body. We reset computer and relearned idle several times, ok for a while then starts stalling routinely again. Can you help with what to do next? Owner, driver, wife is getting frustrated with the big money spent to no avail to date and I am worried it will stall at a dangerous time, when she is driving. She loves the car - has had it for 20 years and wants to keep it. I need it to be safe and reliable for her.

It could be the tcc solinoid on the trans.disconnect plug on tran. you wont have overdrive but it shouldnt stall. if it does it is something else.

How many miles are on the car?
How much oil are you using?
Has anyone done a compression test?

My guess is a cracked ignition coil. I had a similar problem on my 95 Buick Roadmaster.