I agree it could be the throttle body or idle control valve.

I'd also look for a vacuum leak somewhere near the TB. You can find it by spraying brake cleaner around the various vacuum lines while the car is idling.

I had this problem with my CRX for months and couldn't figure it out - it was a bad coolant temp sensor which was giving the IACV fits.

Good luck.

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2002 X5 3.0i