Car warms up, struggles to idle / struggles at slow speeds

When I start cold, it runs fine. Once I've almost made it to work and the temp is at normal operating temp, and I've come to a stop, the car insists on stalling. Then it' sa struggle to keep it moving and keep it from stalling... Limping it's way to a parking spot. Yesterday, it stalled and I rolled into a parking spot. Today, I parked and it stalled. Only 67k miles on it, changed the plugs and coil pack (yesterday), thinking it was those. Sprayed a little throttle body cleaner into the throttle body. Anybody ran into this issue?

Does the check engine light come on? If not, are there any pending codes in computer?

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Originally Posted by EAD15

Does the check engine light come on? If not, are there any pending codes in computer?

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I did hook up an analyzer, and once I learned how to use it, it had 4 fault codes pointing to "O2 sensor circuit low voltage bank 1, sensor 2"
And one fault code pointing to "Idle Air Control System RPM's lower than expected" I guess that's just telling me what I was already seeing... "Struggling to idle"... Which is due to the after CAT O2 sensor failing?

Given the symptoms, I would suspect the downstream (after cat) O2 sensor is/has failed. O2 sensors can only feed usable data to the computer once they've heated up substantially.

As I understand it, before the sensors are hot enough the computer ignores the sensor data (open loop) and mixes the fuel at the stoichiometrically "ideal" fuel-air ratio. Once the sensors are hot enough, the computer starts using their data (closed loop) to tweak how much fuel is actually needed to burn fully.

I suppose it is possible that you have an electrical problem with the wiring to the sensor, but swapping out the sensor is faster and easier than chasing an electrical gremlin that may or may not exist. The sensors aren't cheap, but at least then you would have a known good part if it doesn't fix the problem.

Personally, I would suggest avoiding the "universal" ones that require you to splice the wires as I have had bad luck with them.

Edit: I would expect the code for the Idle Air Control system is a side effect of the O2 sensor problem and would go away once the sensors are working properly.