SES light on? Any code?

If it's just low idle, it's starvation of either gas or air. Not saying 100%, but 60~70% based on my experience.

Check code first. If no code, measure fuel rail pressure. Just this on top of my head, sorry.

GL

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01' 3.0i E53 (M54) with 164,000 miles
07' 3.0si E83 (N52) with 134,000 miles
08' 3.0si E70 (N52) with 91,000 miles