IAC idle air control, TPS throttle position sensor, CTS coolant temp sensor.
It could be any of them. The IAC and the TPS control the idle speed, but the CTS it what I am leaning toward based on your description. The CTS, located in the thermostat housing, is a thermistor type sensor. As engine temperature increases, sensor resistance decreases. The ECU judges engine temperature by the sensor output voltage and provides optimum fuel enrichment when the engine is cold. If it is not working properly, it can tell the computer it's cold and cause a rich mixture. Thus, your rich mixture (bank 1) and poor idle.
Now keep in mind, there is a coolant temp switch and coolant temp sensor. The sensor, located on or near the thermostat housing, is the one you are after. It is what communicates with the computer.
Let me know if this helps.
Tuesday, December 15th, 2009 AT 9:48 PM