Stalling n idling low

What you've described is a real common problem on Chrysler products with a real easy fix. Chrysler uses a lot of Mitsubishi parts so your car may have the same problem. It is caused by disconnecting the battery or letting it run dead, or, as in your case, unplugging the Engine Computer. It loses its memory and has to relearn "minimum throttle" before it will know when it has to be in control of idle speed. Until then it will idle too low, will be hard to start unless you hold the gas pedal down 1/4", won't give you the nice idle flare-up to 1500 rpm when you start the engine, and will tend to stall at stop signs. I don't know if your car is the same but for Chryslers, to meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals.

I kind of guessed that but if there's a different cause of low idle speed the lost memory will be in addition to that so you might be looking at two different problems.

You can also view the idle "steps" the computer has set the idle speed motor to but you would need a scanner to do that. Typical on Chrysler products for a good-running engine is step 32 out of 256 steps. If yours is on step 0 the computer hasn't relearned minimum throttle yet. If you find it on a rather high step, like 50 or more, the computer is trying to raise the idle speed but not having success. The idle speed motor can get gummed up on very rare occasions but you already replaced it. It used to be much more common for the air passage to become blocked with carbon so increasing the idle step had no effect. That used to happen on Chryslers mostly with the 3.0L Mitsubishi engines but today we have cleaner fuels so we don't see that very much.