My 16v 201 had idle, stalling, surging issues only when warm. Turned out the coolant temp sensor was out of specs almost 300ohms when warm. As a quick test I put a 400 reistor ($1.00). It settled down immediately. I also suspected a leaking cold start injector. That would also explain poor performance when warm.

Get some resistors in various ohms from radio shack and pull the little plugs off of the CTS. Make contact to see if it changes idle.