Idle fluctuation / TA related issue or ICV?

'08 E90 w/ 66k, stock.

So bank 01 throttle actuator is going bad and tosses the error code. Been saving up to replace after the IRS took their pound of flesh out of my fun money account. Still driveable if I stay smooth on the go pedal, but safe mode if I decide to have some fun... Anyway, this isn't about that.

I've also noted my idle fluctuates up and down cold or warm engine, ac on or off, like its looking for something (seeks between 500 to 800 rpm); I wouldn't call it rough, but it is not a stable idle. It is also not tossing an error code.

I read the Idle Control Valve is also a common issue and it's right there while I'm doing the TA's. I vaguely recall it being replaced under warranty a long time ago.

So the question is whether the throttle actuator issue would also cause the rough idle? What are the symptoms of a ICV going bad? I'd hate to spend a day getting in there replacing the TA's just to repeat it again for a ICV a few weeks later.

Thanks...

When my TA went bad, I noticed no change at all in how the car felt or behaved. It threw the code here and there, but always felt fine. When I had my ICV replaced, there was also a code, but the idle was irregular...higher than normal and fluctuating. Hope this helps.

My car just had the TA's replaced. No idling issues prior to replacement

It could be your fuel tank breather valve. Check this post: http://www.m3post.com/forums/showthread.php?t=1273927

If you are having the idle fluctuation with stalling, change the fuel tank breather valve. As long as you know your ICV is not bad. You would have a code for the ICV. By changing the fuel tank breather valve, if will fix your idle fluctuation and stalling problems. Please see the above link on how to get to it.