Car stalling at idle

I have a 1997 Avenger ES 2.5 engine with 153,000 miles on it. I do most of
the mechanical work on the car myself but simply cannot figure this one out.
The car will stall at an idle from time to time...when it is cold or after it is
warmed up. It will start right back up but the stalling is getting worse. When it
is running the engine does run a little rough but not too bad. I have changed
the TPS switch, cleaned the throttle body, replaced the fuel pump and filter
around a year ago, replaced the fuel pump relay, all to no avail. A friend of
mine in Florida who owns an auto shop says it could be the distributor coil
and the distributor would have to be replaced. If that is the case this would
make the 3rd distributor which was replaced for reasons other than stalling.
There is no light in the dash so I am not sure if I can have any codes pulled. I
was going to replace the EGR valve but not sure if that is the problem and I
do not want to keep putting parts on the car which may not repair it. Please
let me know what you think may be wrong.