what is reason/solution for 2004 f250 (gas) stalling in stop and go city traffic on 2004 Ford F-250 Super Duty

after 1st occurrence, had regular service and replaced air filter. Problem recurred next time truck was in slow/standstill city traffic. To mechanic again,diagnostic computer identified a problem with speed sensor in the transmission. Sensor replaced and trans fluid changed. (approx. $400)and problem has resurfaced in less than 1 week - all occurrences in slow/standstill city traffic (approx. 150,000 kms)

2 answers 4 comments
Try the idle air control valve and a throttle body service
Thank you Girliy2000 - that sounds logical, wouldn't you expect a long time pro mechanic to have the same suspicion?
I would!!! Especially since it's common!!
Actually #-1 post a pretty good answer! Light on? If so another scan test is needed. Post the code number(s) and we will try to help. Autzone will scan it for free.
Yup, I'll do that. thanks.
U bet.