Q: Stalling at low speeds and idle.

I recently had autozone run the computer on my truck and it came back as failing cat and ignition coil. I eliminated the cat and replaced the ignition coil. The truck runs much better, but i hit that same issue with the killing. again, it runs better, but the killing hasnt stopped. should i replace the wire from the ignition coil to the distributor cap? i did a full tune up about 3 years ago so all the wires and spark plugs were replaced. i dont remember if i replaced the distributor cap or not. i think i have it narrowed down to either the wire from the ignition coil to the distributor cap, or the distributor cap. thats my guess. the way it kills is at an idol or at take off. now that i replaced the ignition coil and cut the cat off it starts back up much easier (before it would have to sit for hours). suggestions?

My car has 220000 miles.
My car has an automatic transmission.