RE: 2003 Dodge Ram Stalling question?
EGR valve issue usually stalls at any time, running down the road, at a stop light, etc. Not saying for sure that it's not, and at the age of your truck, if it's the original valve, it's time. But your symptoms suggest it's the PCM issue.
A flash at the dealer might be in order.
I have a cheap fix you can try however. I had a discussion about this at my local Performance Shop one day. It used to happen to me EVERYTIME I backed up my driveway. I had to stop in the road, shift in reverse, cut the wheel, and if I didn't give it a good bit off gas right away, it died.
I happened to put a 180* thermostat in (not for this issue, of course, I just wanted one) but I noticed the stalling stopped happening.
Anyway, I inquired about how this could have fixed it, since it was the only change I made in between this stalling and non-stalling sequence.
The guru at the performance shop pulled out his laptop and showed me that the 'stat caused a slightly rich state, due to the PCM thinking that the truck is still warming up, so it gives a little more gas (idle also increases just a hair) This is just enough to keep the rpm's up enough not too stall (it's a miniscule difference, but in my case was just enough to keep it from stalling).
As this thermostat is a cheap and super easy install you could do in your driveway in 15 minutes, IMO it would be worth a try, not to mention there are other benefits to having a slightly cooler thermostat.